OK, lots of great guesses with our contest the other day, but we had four people with guesses within 0.3 HP of the actual measured at the wheels, so that means four T-shirts will be going out. I'll be putting the names and official announcement in next thursdays video, but thanks to all that entered!
I really think that if you do some home porting on the heads and upgrade to a trailblazer SS intake you'll gain quite a bit with the upgraded cam. Also, as far as power adders, a twin screw supercharger is going to be better than a roots supercharger if you go that route.
Tbss Intake would see good gains porting the heads would see a tiny gain for the time and money spent. Those heads stock can support more power then most 4.8s can make
They both have their place. My choice was easy. I bought a Volvo 240 to shove a 6.0 in to it. My truck already had a 6.0, so instead of buying another 6.0, I bought an 8.1 for the truck. Two projects with one engine 😁
Man the difference between a LR4 4.8 and a LQ9 6.0 is really eye opening. My LQ4 made 409whp with a set of speed engineering long tubes and dual 3”, a 218/224 cam and a TBSS intake finished with 90mm throttle body. I am at sea level with great air so that does help.
Considering the LR4 and LM7 share the same bore, different stroke, and the LM7 and LQ4/9, share the same stroke but the LQ4/9 is larger bore. 293, 325, 364CID 7.4 is 454, 8.1 is 496CID
Well, you just stomped the LS with the boat anchor in every category including dollar per hp, then concluded that the LS is better. Lets just agree that given the same modifications, the larger displacement engine usually out performs the smaller.
the problem is, you have to locate & buy the 8.1 engine to swap in which usually aren't cheap. Standard cab 4.8 and 5.3 trucks are dime-a-dozen as long as you'll settle for a high mileage used one.
Magnusson is my vote. You already made the exhaust and have a turbo setup. Will really wake up the bottom end and make it feel more like that big block you love ( I do too super stoked for the stroker build!)
You are supposed to open the fender holes up. They are 75% shrouded compared to the airbox inlets. Die grinder and a few minutes work opens it up to match the airbox tubes. Just like a gasket match.
This has been an awesome quest. You are a very talented do-it-all, a jack of all trades. Wish you (and your trucks) the best in the coming future and will be watching the additional improments that you will have for them.
For me, I love the LS2 in my TBSS and it makes for low effort power - I'm in my 50's, I'm done with blowing stuff up. Mild tunes and bolt ons, long tube headers, extensive aftermarket support, easy to tune and diag with HP Tuners, and no DOD makes this particular LS2 my sweet spot - I'd drop it in anything. But hey, NA vs NA, big displacement will win the numbers game. But I'm so dialed into the LS platform, and I'm just done spending time working on stuff rather than simply driving it - so the easy way out for me is anything LS. Great video - I love your methods and hard work and conclusions, they're nuanced and comprehensive. Thanks!
You can just make a pull without the air filter to really narrow it down. Then you'll know if it's mostly filter or intake piping. You can keep going with timing until you don't make any gains and adjust knock sensors accordingly on the same day with the same fuel. You won't hurt an NA engine that way, the knock sensors will pull timing.
My 8.1 Suburban gets 10 to 11mpg at 80mph with 33x12.50, 4l80e trans, and 4.10s. 7.5mpg in town. Cool thing is my mileage doesn't change unless I'm towing 8k+, or have a large cross section trailer for wind to grab. I can be solo, or at max passengers and payload with a trailer and it doesn't change. I'm also in Utah. I'm cammed, roller rockers, e fans, long tubes, dual 3" exhaust with x pipe, Volant ram air, 4l80 mods, and tuned. When stock i got 12mpg freeway, 9 in town.
Context matters. Emphasis on race over street? LS, hands down. Everyday driver, (towing, hauling, longevity, low strung), big block all the way. The 496 w/a mild cam, exhaust work, intake help would have probably yielded ~400 HP and well north of 500 ft/lb. Perfect to pull the trailer, load it up at Home Depot, then blow the tires off at the track.
Thank you for using your 4.8. everyone picks the low hanging fruit and gets the 5.3 or 6.0. not everyone has the space and time to swap out the 4.8 to 5.3/6.0. Imma do this with my two Silverados but they'll both stay 4.8. then boost. Thank you again! I fell in love with the 4.8 and I can't seem to get away from it...
I agree might not be the big horsepower monster but that Little motor Winding up Sounds so good yes you could make more power With bigger one But I love the underdog It's the C biscuit
I really enjoy the BBC vs LS comparison, Turbo's are my favorite form of forced induction but will be gladly following along regardless of which way you go. I would be curious to see you make a 0-60 run without the air filter and that would tell you if the restriction is the air box, filter, or both.
Have you not done the basic performance changes to the Power Enrichment? You don’t need any Delay and PE needs to be set at 40-50% throttle. Also do a TPS reset to make sure it’s scaling properly. JD
PE should be set throughout the range and should ramp in around the same time as the power band for the cam that you're using . You definitely don't want it running 50 mmHg and ramping in at 2000 rpm so every time you look at the gas pedal you're in PE . That's a fantastic way to waste fuel and ruin power . You really should have a delay unless you want your computer pulling fuel everywhere you go unless you plan on driving with your foot to the floor all the time . Just taking off from a stoplight you pull 75 mmHg . And in my case that's with a 232/241 cam that robs a s*** ton of vacuum . Stop raping your PE and properly set your VE .
Kids kids kids, i own many big block chevys. I also own a truck with a ls 6.0. First i own a stock 396 L89 big block. Only added headers. This engine is NA with a carb. It put out on the wheels 416hp and 496 tq. Now i own a 1971 Baldwin Motion camaro, i have owned this camaro since 1982. It gas a 454 LS7 from 1971 installed by motion. Only added a 3.5 dual exhaust and hooker headers and it is carburetor. At the wheels it has 577hp and 608tq NA. I will keep my big blocks!!!!!
Following you closely, and trying to keep up financially! Caltracs are on my list for the 81 stepside, but not the 99 AWD. The 6.0 / 6l90 combo is in the 81, and yes I know you said dump that trans, but I think with some higher line pressures and a few other things, it may survive. I did keep the extra 80e, just in case. Stay tuned my friend, and I definitely will too!
Very hard to beat an LS for inexpensive and solid power gains. I've had three, including an LSA and they all have been home runs. 8.1 is intriguing as it incorporates a lot of LS technology, and it's a great motor.
I'd love to see a procharger on the step side. A roots or screw blower would really help the low end torque but I feel a procharger would really play into the 4.8s short stroke and need to rev out. Either way, excited to see where this goes
Nice that the 8.1 makes those numbers on 87 octane gas. Doesn't need premium. Also with the numbers the 4.8 is making I don't think the 3 inch tube is a restriction at all. A 3 inch exhaust would be ok at those numbers so the intake would be too. Maybe pull the filter out of the box and run it a few times and read the kpa
absolutely awesome comparison and well done videos, loved every minute of them!!! would love to see how much you spent on the 8.1 to turbo it and use the same budget to turbo/s.c the 4.8 and then compare the numbers again! I love the David vs Goliath theme so I say build out the 4.8 before you swap it out.
@@LawrenceTolman I'll definitely check it out! yea I think it'd be awesome to see what the $$/hp is once they both have forced induction and same money spent as well as which one is quicker on the strip/draggy 👍👍
I’m leaning towards your restrictions being TB, even with a 4” intake tube, that’s still the deadhead point of stacking air and just bottle necking it right there, but my guess is also if you stepped up to a bigger TB you’re going to lose some on the bottom end. But I agree with most everybody, it’ll respond best with some boost or nitrous and the bigger TB
In my experience the small spikes you see on the wideband under full throttle are misfires. Not complete misfire, but small misfire. That could be part of your missing power.
Thanks for the fun comparison LT! I’ve owned a 8.1/Allison 2500HD; all said I would rather have an LS in a truck in most 1/2 ton scenarios for the same reasons you mentioned. Especially an aluminum block, just so much lighter, much much bigger aftermarket support, higher rpm = more smiles for me. Conversely, the 8.1 makes more sense where weight is a good thing or you’re running 38”+ tires offroad.
Great comparison surprised even with fuel injection at the 4.8 still isn't making one horsepower per cubic inch especially the 8.1 stock boat anchor had one in a 2500 heavy duty with a factory 410 and an Allison 6 speed it seemed way down on power plenty of torque but yes a supercharger or turbo would have definitely been fun and pept that motor up seems as though it's been replaced by the 6.0 that over the years has become more efficient and definitely better gas mileage
Similar times on the 4.8 as my 72 el Camino here at 1200 ft elevation. I’ve got a gen 3 5.3 with a tbss intake and 90mm throttle body, 4l80 and 2.73 gears. Best times on my draggy 0-60 8.03, 1/8th mile 10.45 @71. In the process of change to a 9 inch and 3.70 gears. Turbo soon. Love the content.
If you're swapping, you may as well go with the biggest LS you can afford. No LS is RPM limited, so big rpm just means bigger power with a bigger LS. Unless you intentionally want to keep it mild.
I did similar upgrades on my 07 Tahoe a couple of years ago. Custom Cam new springs full rebuild full headers intake etc. spent $3500 at the engine shop. Dino in SC shows 320 hp 321tq at the wheels. I did have a full day with a reputable tuner. 5.3 and a generation newer. Still get 18mpg. Wife drives it everyday now. Most likely an elevation issue for you. The 4.8 supposed to have thicker cylinder walls which makes it better for boosted applications. Love the challenge. Smart move
I enjoyed the video. I especially appreciate the methodical approach to tuning and the practical suggestions on measuring performance improvements without a dyno session. I found it really helpful. The air box hack is a great example of quick low cost way to test a hypothesis and then using the data logger to infer the improvement. Very clever, thanks.
As you were doing the acceleration tests, I kept thinking - put it in 4 high! Would have liked to have seen the impact of throwing everything it had at it from the launch. As for mods... it's a toss up and hindsight is 20/20. I ditched my factory 4.8L/60E in my 2001 Silverado for a low mileage LQ4/80E. I paid right at $1000 for the engine and transmission. Add tuning, the wiring for the transmission and a new crossmember, a yoke and conversion u joint, headers, exhaust system... you get the gist. I was about $2500 into it. Then add cam, valvetrain, TBSS intake, 92mm TB, injectors and fuel pump... that put me about $1000 deeper into it. On 87 octane it has done about 350 rwhp, and 380 rwtq. (Small camshaft) I am going to retune it on 93, get updated numbers. Then take it to the track on sticky tires to see where it is at. Next will be a set of ported heads, larger cam, FAST LSXRT intake, and a 3600 stall. Eventually a single turbo. Do I regret not just throwing a cam and a 76mm at the 4.8? Almost, but not quite. I know my modified 6L is going to make tons of power on relatively low boost levels. Thus, it will be easier on parts and hopefully live longer.
I would have done a 4x4 pull, but the 4wd system is buggy on this one, and doesn’t work half the time. (I think the service 4wd light was on in a few shots). But soon when the awd swap is done, we can really let it rip with no traction problems.
@@LawrenceTolman might be the actuator. My 05 Sierra stopped engaging into 4wd. (Push button) I took it off the road to fix a bunch of things, that actuator is on the to do list. Switching to AWD, it must eliminate that. I'm looking forward to seeing it rip on an AWD launch.
They both need heads and an intake manifold, but as the 4.8 sits, if you dumped 29.4 psi of boost in it you are looking at ~556 rwhp/~667 crank, if it can move the air and fuel.
My old truck. 2004 Silverado 2500 hd, I had a 2-1 magnaflow with the 4” tailpipe, afe cold air intake, on my buddy dyno, it made 278hp/340 torque roughly, glad you bought the 4” tailpipe from magnaflow, that little 4.8 that could can’t wait to see you do more with it
You should hands down do the whipple 2.9l if you are thinking about a roots style, because it has the front inlet, and cost the same as the smaller 2.3l….. then if you go up in engine size aka 6.0 or 6.2 you won’t have to get a different blower!🙌🏼🔥
Wow that LS made the same power a stock Ford 4.6 3valve makes. the 4.8 is gettin there. I’m super excited for the big block stroker. Can’t wait to see that torque monster eat!!
Here's the thing: LS is king for the aftermarket. BUT your 8.1 is displacement... now queue in the 572/632 crates that GM has announced this past year. 572 in the COPO and the 632 that makes 1001HP. Now that I've completely thrown a monkey wrench in it all. Loved the series.
The 4.8 sounds great and I thought that the HP numbers would be higher but I forgot that you are at a higher altitude, how about doing some porting on the heads and maybe having the heads milled a little bit for higher compression and/or swapping out the pistons for a higher dome piston instead of milling the heads? Just a thought. On that airbox where you drilled the holes, take it out and cut it so that the bottom half is more shaped like a "cage" so the airbox is almost totally unrestricted. Just my 2 cents. Thanks for the great videos and looking forward to seeing more!! Hope you and your family have a Merry Christmas!! :)
If you are planning to beef up the 4.8L, at least all aftermarket forged crankshafts are roughly the same price, either 3.622" or even 4.00". That little iron block with a 4" stroke will become a monster @ either 363CID at stock bore or even up to 383CID if you want to stretch the cylinders out a bit to LS1 bore size.
It would be neat to see the 4.8 with a nasty turbo set up. I’m building a 408 stroker for my rcsb right now, and the numbers I see on these boosted 4.8s make my build look like a waste of time!
The 4.8 is definitely choking for induction. And I think the cam is a little tame for NA power, but it should be very good for FI. All in all, the mods you made are really just pulled punches for NA, but they’ll pay dividends when you have forced induction. In the meantime, having more torque and horsepower everywhere is no small achievement, well done!
i had 04 chevy 1500 with a 6.0 cam,milled 243,nnbs intake,90mm tb,lt's,80e,4.30 gears, made 417hp/414tq @ the wheels. my mud truck has 8.1/allison combo and there is no comparison when it comes to torque.. now the 8.1 is cam,d intake mod,lt's, 90mm tb,roller rocker its a beast now.
The 8.1 is 395ci (a tad short of 396ci). The 8.1L also sounds much better than the 4.8L. The low end torque of the 88.1L is what gets the quicker 60' time. Higher horsepower on the upper end helps pull harder at speed. The 4.8L needs power adders (modifications) to even approach stock big block numbers.
A good rule of thumb is on a NA motor you lose about 3% power per 1,000’ of density altitude. At your altitude you stand to lose 12-15% power compared to sea level on a standard day. That may be where the discrepancy in the 4.8’s expected power is coming from.
I was thinking the same thing. His kpa is up then goes down then back up how is that in the air box or tube?? Lol it’s the intake. I have the same tube, box and filter and I’m at 98-101 kpa all day long at WOT of course that’s at sea level
On that filter box modification just wanted to mention it’s very common for bmw guys to do a “charcoal filter” delete. Idk if Chevy did this where they put an activated charcoal filter after the regular air filter, but if they did and you remove that you might be able to rid some of that restriction and maybe gain some throttle response. Did it on my e92 and I makes enough difference to notice
I really hope you don't go to a 6.0L or 6.2L, stick with the 4.8L and throw on a supercharger. I'd like to see the "cheap" mackdaddyparts Cadillac setup that Richard Holdener dyno'd or maybe whipple setup. Oh and port the heads which you really should have done while motor was apart.
Far as testing a good one is acceleration rate graph in HP tuners . Gives the ability to see where it's accelerating good and where it may be lacking and you can adjust just areas of the tune in the weaker places . Find if your shift point should be raised or lowered etc.. I've forgotten the pids and math it took to set it up but to give credit where it's due I got it from Goat rope garage here on CZcams
If your going to stick with the 4.8 the only way to get it to shine is with a cam that’ll hold power out to 7500 or so rpm, get a good set of aftermarket heads and a good flowing intake. If your not turning that motor over 7000 rpm, then buy a 5.3/6.0 crank and rods, they’re the same. And swap it in. Then you’d have a slightly higher compression 5.3, and more power.
port and polish your heads, gasket matching the intake. spend some love on the heads. fan modulation for a slightly higher temperature. change final drive for more torque.
The stock 8.1 setup would be great for towing and you said it Best there is no replacement for displacement but the little 4.8 did great considering the displacement and you're turning the 4wd components I think it was a very good comparison because each trucks setup they'll have their place like ugly truck trailering the step side to the track
I don’t think putting a 5.3 in to replace a 4.8 would’ve been worth it, there isn’t much of a difference there, I definitely agree with a 6.0 bc that’s a totally different beast. I would love to lq9 swap mine.
A 5.3 makes like 10 more hp, definitely not worth it. A 6.0(lq4) 15 more than that.. we aren’t talking huge Gains in power.. the biggest difference is the torque and shift(lower) in the power band.
@@matt6951 6.0 would be a pretty good jump, not only for the horsepower but the torque. I honestly would love to see the 4.8 get some love, but it's hard to not just go with the 5.3 or the 6.0 for around the same cost.
@@OGbqze 6.0s usually go for quite a bit more than 4.8s and 5.3s(which tend to be about the same on average) For whatever reason.. they are not, totally different beasts. They make marginally better power stock, not enough to justify the cost difference. I’ve had them all, 4.8, 5.3, 6.0, even a 6.2
We have a 5.3L '04 Silverado and it's ok, but my BoltEV doesn't care about altitude and does the 0-60 dash in just less than 6.5 seconds. Both serve their own purposes and we are keeping both....but most of the miles are run in the EV.
I think it was good testing with good results however had you started with a 5.3 I think the numbers would have been much better. Personally I just like the 5.3, the 4.8 always seemed slightly lacking to me. Boost would obviously change that. Haha
Here's what I know the 5.3 starts out more hp and responds better to modifications. If you don't think so, jump over to Richard holdner's channel and watch his 4.8 videos and 5.3 videos, he has many 5.3 builds that go over 500 chp but the 4.8 do not.
I have a 98 single cab stepside with a 8.1 and allison 1000 transmission , its flawless and love it. in my opinion the 8.1 is under rated . i would like to see more aftermarket performance parts out there.
Would love to see a roots supercharger on that 4.8. I don't know if they're popular as turbocharging is so common, but I just love the sound of that little LS revving out. The 4.30s would be right at home, no doubt.
Hey LT! You are always putting out great content! Thank you! I’m in the process of swapping my 94’ K1500 and was wondering about the dual 3” to single 4” exhaust and how it would sound. Then how convenient for me you are doing the same exact set up I’ve been building in my head! Haha. Looking forward to the completed system with tail pipe! Thanks again, Keep up the good work!
275hp is good for 4700/4800 feet. Thats close to 300hp at sea level. Intake and larger throttle body will be 10whp. You should have enough subs to get a Maggy and or whipple at cost (assuming you advertise the blower on a few videos). Youd be suprised those companies work with youtubers/ social media builders more then youd think. Id email them the truck videos. See if they cant send u a new 2650 at their cost.
The most unfortunate part of this whole adventure is you didn't have a 8.1/Allison combo to begin with. For anyone considering all of this adventure, a 6.0 covers all the bases. It has enough to it to make great torque, and it has all the LS support for HP. The smaller LS are more affordable, ut not by much really. The 8.1 is king of the tire roasting pure raw beast muscle though. Dyno numbers be damned, if you aren't old enough to remember driving old big block cars, it is impossible to explain the difference in driving experience.
I have a 8.1/ 80e in a 1/2 ton regular cab short bed 2wd. It is the closest thing I have ever driven to the 70s muscle cars. Even have roll up widows to complete the feel haha. I love it so damn much
K&N are not worth the money. When it comes to filters and restriction, the total surface area of the filter is going to determine how much air it can let through. Some media is better then others, but just to start out with you should put the biggest filter you can fit under there to allow the most surface area. At some point the filter will flow more air then the tube can.
This comparison of data and thoughts/conclusions is really cool. But I’m honestly only here for one reason…what will he name the little 4.8?!? Lol. Only kidding about being here for one reason. These videos are great, LT! Your knowledge and research is top notch. Keep up the good work!!
My 00 Sierra BONESTOCK 4.8 single cab stepside 3.42 gears 2wd ran a best of 16.4 on the 1/4 at sealevel. I had done a tuneup prior to racetrack time. It had around 70k miles. Pretty slow in my opinion.
What’s the weight difference in these trucks? I’d be curious how much faster the SCSB truck would be with the “naturally aspirated” 8.1 like in the ugly truck.
Unless you duct air from in front of the radiator cutting hole in the filter box may reduce horsepower. Cold air intakes rarely add power they simply keep power by not having to pull timing etc because the intake is sucking in hot air A must is an air intake temperature sensor and manifold temperature sensor that you can data log to see if the ECU is pulling timing to prevent knocking.
The Amazon 4" intake is what I'm using. But I have completely shrouded the filter from the engine and rad. Much better performance just sealing off from those 2 areas
Playing with timing on an na motor will not affect air flow. given throttle positions and rpms (assuming equal weather conditions) will result in the same maf readings for given rpms.
4.11S CONVERTER RAISE SHIFT POINTS AND REV LIMITER had caps lock on 2011 4.8 makes about 260hp to wheels stock with muffler and afe dry flow do all synthetic trans engine differential fluid aftermarket plug wires. If older 4.8 port polish throttle body.
I did not follow or understand your logic for using the MAF to determine engine power based on ignition timing... How is airflow through the motor affected by ignition timing? Both valves are closed when the spark goes off. Can someone explain to me what I'm missing? The only only possible thing I can think of is that by making more power with more advance you'd somehow gaid additional scavenging effects on the exhaust event which would possibly draw more air through the motor? That seems really hokey to me though because at perfect efficiency, the motor is an air pump, and knowing the cylinder volume, spinning the motor at any specific RPM will move X amount of volume of air through it... Valve timing could change things, but ignition timing, I'm not biting on that.
Sure the LS has a gate following but the mighty Big Bock has been here for a long long time kid, you wanna go fast ? there is still no replacement for displacement Big Block for the win !
Once a 4.8 has been pulled there is no sensible reason to put it back! 5.3s are ALMOST FREE! Literally, the only reason the 4.8 exists is so that Chevy could give the option to poor people and fleet managers. It cost them exactly the same to manufacture, they just purposely neuter it with half a crankshaft... If you're not poor/fleet manager, a 4.8 has no reason to exist. It's like a 2WD Jeep. Or a 4 door Corvette.
OK, lots of great guesses with our contest the other day, but we had four people with guesses within 0.3 HP of the actual measured at the wheels, so that means four T-shirts will be going out. I'll be putting the names and official announcement in next thursdays video, but thanks to all that entered!
well now that this series is done, there is no point to your channel. it holds no more entertainment value. peace!
My 88 reg cab short bed.....I'm dropping the 502 4l80e package deal in it. Big Block all the Way!
LSA WITH a turbo, if you're going for the supercharger only approach though go for a twin screw (e.g. KB/whipple)
Hi Lawrence, where did you source the 8.1??
(I'm in Riverton)
@@2S1L3NT they can be had from suburban 3500s, many 2500+silverados, the avalanche 2500/3500, and most gmc equvalents
I really think that if you do some home porting on the heads and upgrade to a trailblazer SS intake you'll gain quite a bit with the upgraded cam. Also, as far as power adders, a twin screw supercharger is going to be better than a roots supercharger if you go that route.
Port the heads, twin screw it!
Tbss Intake would see good gains porting the heads would see a tiny gain for the time and money spent. Those heads stock can support more power then most 4.8s can make
They both have their place. My choice was easy. I bought a Volvo 240 to shove a 6.0 in to it. My truck already had a 6.0, so instead of buying another 6.0, I bought an 8.1 for the truck. Two projects with one engine 😁
Destroy that Volvo asap
Man the difference between a LR4 4.8 and a LQ9 6.0 is really eye opening. My LQ4 made 409whp with a set of speed engineering long tubes and dual 3”, a 218/224 cam and a TBSS intake finished with 90mm throttle body. I am at sea level with great air so that does help.
Considering the LR4 and LM7 share the same bore, different stroke, and the LM7 and LQ4/9, share the same stroke but the LQ4/9 is larger bore.
293, 325, 364CID
7.4 is 454, 8.1 is 496CID
Yeah I’m surprised too! My 5.7 LS1 with a TSP 233/239 cam, headers and a homemade CAI made 382whp.
@@TheMotorman80 why wouldn't you just get an slp intake?
@@xpeacemaster Because it’s an LS1 in a 1995 S10. SLP doesn’t exactly make an intake for that, plus it’s way cooler to fab up your own stuff!
@@shadowopsairman1583 not sure what any of this has to do with his comment...
Well, you just stomped the LS with the boat anchor in every category including dollar per hp, then concluded that the LS is better.
Lets just agree that given the same modifications, the larger displacement engine usually out performs the smaller.
the problem is, you have to locate & buy the 8.1 engine to swap in which usually aren't cheap. Standard cab 4.8 and 5.3 trucks are dime-a-dozen as long as you'll settle for a high mileage used one.
@@91CTD and? That doesn't disprove what the original post states.
Magnusson is my vote. You already made the exhaust and have a turbo setup. Will really wake up the bottom end and make it feel more like that big block you love ( I do too super stoked for the stroker build!)
You are supposed to open the fender holes up. They are 75% shrouded compared to the airbox inlets. Die grinder and a few minutes work opens it up to match the airbox tubes. Just like a gasket match.
This has been an awesome quest. You are a very talented do-it-all, a jack of all trades. Wish you (and your trucks) the best in the coming future and will be watching the additional improments that you will have for them.
Thanks!
For me, I love the LS2 in my TBSS and it makes for low effort power - I'm in my 50's, I'm done with blowing stuff up. Mild tunes and bolt ons, long tube headers, extensive aftermarket support, easy to tune and diag with HP Tuners, and no DOD makes this particular LS2 my sweet spot - I'd drop it in anything. But hey, NA vs NA, big displacement will win the numbers game. But I'm so dialed into the LS platform, and I'm just done spending time working on stuff rather than simply driving it - so the easy way out for me is anything LS. Great video - I love your methods and hard work and conclusions, they're nuanced and comprehensive. Thanks!
You can just make a pull without the air filter to really narrow it down. Then you'll know if it's mostly filter or intake piping. You can keep going with timing until you don't make any gains and adjust knock sensors accordingly on the same day with the same fuel. You won't hurt an NA engine that way, the knock sensors will pull timing.
Problem is if that's a oiled KNM air filter it dirtied up the maf
@@crautoguy8384 If it wasn't dryed for 12 hours maybe. Or if it isn't K and N filter oil. It dries completely overnight.
I've enjoyed following your builds. The stepside reminds me of my buddies truck. He put a Magnusson TVS1900 on a 4.8 and it made good low end torque.
I did this but on a L9H 6.2 i love the trucks it’s amazing also full bolt ons.
How does the fuel economy of the 4.8 and 8.1 compare at 75mph? For those of us that rack up highways miles.
My 8.1 Suburban gets 10 to 11mpg at 80mph with 33x12.50, 4l80e trans, and 4.10s. 7.5mpg in town. Cool thing is my mileage doesn't change unless I'm towing 8k+, or have a large cross section trailer for wind to grab. I can be solo, or at max passengers and payload with a trailer and it doesn't change. I'm also in Utah.
I'm cammed, roller rockers, e fans, long tubes, dual 3" exhaust with x pipe, Volant ram air, 4l80 mods, and tuned. When stock i got 12mpg freeway, 9 in town.
@@davemcdaniel4856 bigger engines are affected less by towing ford even said they used the new 7.3 gas engine to save fuel.
My little 4.8 gets 19 per the gallon on highway my older 99 suburban 8.1 got like 9mpgs
Context matters. Emphasis on race over street? LS, hands down. Everyday driver, (towing, hauling, longevity, low strung), big block all the way. The 496 w/a mild cam, exhaust work, intake help would have probably yielded ~400 HP and well north of 500 ft/lb. Perfect to pull the trailer, load it up at Home Depot, then blow the tires off at the track.
Thank you for using your 4.8. everyone picks the low hanging fruit and gets the 5.3 or 6.0. not everyone has the space and time to swap out the 4.8 to 5.3/6.0. Imma do this with my two Silverados but they'll both stay 4.8. then boost. Thank you again! I fell in love with the 4.8 and I can't seem to get away from it...
I agree might not be the big horsepower monster but that Little motor Winding up Sounds so good yes you could make more power With bigger one But I love the underdog It's the C biscuit
I really enjoy the BBC vs LS comparison, Turbo's are my favorite form of forced induction but will be gladly following along regardless of which way you go. I would be curious to see you make a 0-60 run without the air filter and that would tell you if the restriction is the air box, filter, or both.
Have you not done the basic performance changes to the Power Enrichment? You don’t need any Delay and PE needs to be set at 40-50% throttle.
Also do a TPS reset to make sure it’s scaling properly. JD
PE should be set throughout the range and should ramp in around the same time as the power band for the cam that you're using . You definitely don't want it running 50 mmHg and ramping in at 2000 rpm so every time you look at the gas pedal you're in PE . That's a fantastic way to waste fuel and ruin power . You really should have a delay unless you want your computer pulling fuel everywhere you go unless you plan on driving with your foot to the floor all the time . Just taking off from a stoplight you pull 75 mmHg . And in my case that's with a 232/241 cam that robs a s*** ton of vacuum . Stop raping your PE and properly set your VE .
Kids kids kids, i own many big block chevys. I also own a truck with a ls 6.0.
First i own a stock 396 L89 big block. Only added headers. This engine is NA with a carb. It put out on the wheels 416hp and 496 tq.
Now i own a 1971 Baldwin Motion camaro, i have owned this camaro since 1982. It gas a 454 LS7 from 1971 installed by motion. Only added a 3.5 dual exhaust and hooker headers and it is carburetor. At the wheels it has 577hp and 608tq NA.
I will keep my big blocks!!!!!
Following you closely, and trying to keep up financially! Caltracs are on my list for the 81 stepside, but not the 99 AWD. The 6.0 / 6l90 combo is in the 81, and yes I know you said dump that trans, but I think with some higher line pressures and a few other things, it may survive. I did keep the extra 80e, just in case. Stay tuned my friend, and I definitely will too!
Very hard to beat an LS for inexpensive and solid power gains. I've had three, including an LSA and they all have been home runs.
8.1 is intriguing as it incorporates a lot of LS technology, and it's a great motor.
I'd love to see a procharger on the step side. A roots or screw blower would really help the low end torque but I feel a procharger would really play into the 4.8s short stroke and need to rev out. Either way, excited to see where this goes
Twin screw it.
Nice that the 8.1 makes those numbers on 87 octane gas. Doesn't need premium. Also with the numbers the 4.8 is making I don't think the 3 inch tube is a restriction at all. A 3 inch exhaust would be ok at those numbers so the intake would be too. Maybe pull the filter out of the box and run it a few times and read the kpa
those are other good factors that I didn't consider, but they do make it appealing for the big block.
LT mic drop. What a grand conclusion a really fun series. Great work LT.
Keep the 4.8 and boost it that’s a build I prefer to see over the 5.3 or 6.0 everybody does those
Hard to beat.
I second boosting the 4.8, procharger?
absolutely awesome comparison and well done videos, loved every minute of them!!! would love to see how much you spent on the 8.1 to turbo it and use the same budget to turbo/s.c the 4.8 and then compare the numbers again! I love the David vs Goliath theme so I say build out the 4.8 before you swap it out.
Hey made a video about a year ago showing the cost to turbo the 8.1, but that was my plan to try to continue the budget comparison in stages
@@LawrenceTolman I'll definitely check it out! yea I think it'd be awesome to see what the $$/hp is once they both have forced induction and same money spent as well as which one is quicker on the strip/draggy 👍👍
yes that would be awsom
I’m leaning towards your restrictions being TB, even with a 4” intake tube, that’s still the deadhead point of stacking air and just bottle necking it right there, but my guess is also if you stepped up to a bigger TB you’re going to lose some on the bottom end. But I agree with most everybody, it’ll respond best with some boost or nitrous and the bigger TB
In my experience the small spikes you see on the wideband under full throttle are misfires. Not complete misfire, but small misfire. That could be part of your missing power.
Thanks for the fun comparison LT! I’ve owned a 8.1/Allison 2500HD; all said I would rather have an LS in a truck in most 1/2 ton scenarios for the same reasons you mentioned. Especially an aluminum block, just so much lighter, much much bigger aftermarket support, higher rpm = more smiles for me. Conversely, the 8.1 makes more sense where weight is a good thing or you’re running 38”+ tires offroad.
Great comparison surprised even with fuel injection at the 4.8 still isn't making one horsepower per cubic inch especially the 8.1 stock boat anchor had one in a 2500 heavy duty with a factory 410 and an Allison 6 speed it seemed way down on power plenty of torque but yes a supercharger or turbo would have definitely been fun and pept that motor up seems as though it's been replaced by the 6.0 that over the years has become more efficient and definitely better gas mileage
Similar times on the 4.8 as my 72 el Camino here at 1200 ft elevation. I’ve got a gen 3 5.3 with a tbss intake and 90mm throttle body, 4l80 and 2.73 gears. Best times on my draggy 0-60 8.03, 1/8th mile 10.45 @71. In the process of change to a 9 inch and 3.70 gears. Turbo soon. Love the content.
No replacement for displacement. The big motors will almost always have more power lol I s dad that people still don't get it .
I think the little 4.8 is the perfect LS if it’s in a lighter truck. I want one to swap in my 99 S10 Extreme.
dream swap man id love an s10 extreme. send it! would be nasty as hell
If you're swapping, you may as well go with the biggest LS you can afford. No LS is RPM limited, so big rpm just means bigger power with a bigger LS. Unless you intentionally want to keep it mild.
@@Levibetz it’s just going to be my daily driver. The 4.8 should give me 300 ish hp and better mpg than the V6.
I did similar upgrades on my 07 Tahoe a couple of years ago. Custom Cam new springs full rebuild full headers intake etc. spent $3500 at the engine shop. Dino in SC shows 320 hp 321tq at the wheels. I did have a full day with a reputable tuner. 5.3 and a generation newer. Still get 18mpg. Wife drives it everyday now. Most likely an elevation issue for you. The 4.8 supposed to have thicker cylinder walls which makes it better for boosted applications. Love the challenge. Smart move
I enjoyed the video. I especially appreciate the methodical approach to tuning and the practical suggestions on measuring performance improvements without a dyno session. I found it really helpful. The air box hack is a great example of quick low cost way to test a hypothesis and then using the data logger to infer the improvement. Very clever, thanks.
Glad you enjoyed it!
Glad you enjoyed it!
Put the 8.1 in the stepside then you would have something when awd happens , love my 8.1 over my 5.3,6.0 , nice video thanks
As you were doing the acceleration tests, I kept thinking - put it in 4 high! Would have liked to have seen the impact of throwing everything it had at it from the launch.
As for mods... it's a toss up and hindsight is 20/20. I ditched my factory 4.8L/60E in my 2001 Silverado for a low mileage LQ4/80E. I paid right at $1000 for the engine and transmission. Add tuning, the wiring for the transmission and a new crossmember, a yoke and conversion u joint, headers, exhaust system... you get the gist. I was about $2500 into it. Then add cam, valvetrain, TBSS intake, 92mm TB, injectors and fuel pump... that put me about $1000 deeper into it. On 87 octane it has done about 350 rwhp, and 380 rwtq. (Small camshaft) I am going to retune it on 93, get updated numbers. Then take it to the track on sticky tires to see where it is at. Next will be a set of ported heads, larger cam, FAST LSXRT intake, and a 3600 stall. Eventually a single turbo. Do I regret not just throwing a cam and a 76mm at the 4.8? Almost, but not quite. I know my modified 6L is going to make tons of power on relatively low boost levels. Thus, it will be easier on parts and hopefully live longer.
I would have done a 4x4 pull, but the 4wd system is buggy on this one, and doesn’t work half the time. (I think the service 4wd light was on in a few shots). But soon when the awd swap is done, we can really let it rip with no traction problems.
@@LawrenceTolman might be the actuator. My 05 Sierra stopped engaging into 4wd. (Push button) I took it off the road to fix a bunch of things, that actuator is on the to do list. Switching to AWD, it must eliminate that. I'm looking forward to seeing it rip on an AWD launch.
They both need heads and an intake manifold, but as the 4.8 sits, if you dumped 29.4 psi of boost in it you are looking at ~556 rwhp/~667 crank, if it can move the air and fuel.
My old truck. 2004 Silverado 2500 hd, I had a 2-1 magnaflow with the 4” tailpipe, afe cold air intake, on my buddy dyno, it made 278hp/340 torque roughly, glad you bought the 4” tailpipe from magnaflow, that little 4.8 that could can’t wait to see you do more with it
You really need a supercharger at that elevation, it’s science 😂
You should hands down do the whipple 2.9l if you are thinking about a roots style, because it has the front inlet, and cost the same as the smaller 2.3l….. then if you go up in engine size aka 6.0 or 6.2 you won’t have to get a different blower!🙌🏼🔥
I love the 8.1 it's basically a modern fuel injected 454 punched out to a 496👌
The 8.1 is a 454 stroked .375 inches.
Well that didn’t age well
Wow that LS made the same power a stock Ford 4.6 3valve makes. the 4.8 is gettin there. I’m super excited for the big block stroker. Can’t wait to see that torque monster eat!!
Here's the thing: LS is king for the aftermarket. BUT your 8.1 is displacement... now queue in the 572/632 crates that GM has announced this past year. 572 in the COPO and the 632 that makes 1001HP. Now that I've completely thrown a monkey wrench in it all. Loved the series.
The 4.8 sounds great and I thought that the HP numbers would be higher but I forgot that you are at a higher altitude, how about doing some porting on the heads and maybe having the heads milled a little bit for higher compression and/or swapping out the pistons for a higher dome piston instead of milling the heads? Just a thought. On that airbox where you drilled the holes, take it out and cut it so that the bottom half is more shaped like a "cage" so the airbox is almost totally unrestricted. Just my 2 cents. Thanks for the great videos and looking forward to seeing more!! Hope you and your family have a Merry Christmas!! :)
If you are planning to beef up the 4.8L, at least all aftermarket forged crankshafts are roughly the same price, either 3.622" or even 4.00". That little iron block with a 4" stroke will become a monster @ either 363CID at stock bore or even up to 383CID if you want to stretch the cylinders out a bit to LS1 bore size.
It would be neat to see the 4.8 with a nasty turbo set up. I’m building a 408 stroker for my rcsb right now, and the numbers I see on these boosted 4.8s make my build look like a waste of time!
Super Charge it lol
The 4.8 looks good with boost right up until you boost the 408.. there is still no replacement for displacement. :)
Just remember though....when you increase displacement if you can gain 100hp na in therory thats 200 hp gained at 15psi
The 4.8 is definitely choking for induction. And I think the cam is a little tame for NA power, but it should be very good for FI.
All in all, the mods you made are really just pulled punches for NA, but they’ll pay dividends when you have forced induction. In the meantime, having more torque and horsepower everywhere is no small achievement, well done!
i had 04 chevy 1500 with a 6.0 cam,milled 243,nnbs intake,90mm tb,lt's,80e,4.30 gears, made 417hp/414tq @ the wheels. my mud truck has 8.1/allison combo and there is no comparison when it comes to torque.. now the 8.1 is cam,d intake mod,lt's, 90mm tb,roller rocker its a beast now.
The 8.1 is 395ci (a tad short of 396ci). The 8.1L also sounds much better than the 4.8L.
The low end torque of the 88.1L is what gets the quicker 60' time. Higher horsepower on the upper end helps pull harder at speed. The 4.8L needs power adders (modifications) to even approach stock big block numbers.
The one ratty tie down on the back bumper and vehicle parked 3 feet in front of you on the dyno had the hair on the back of my neck standing up.
To get the most performance? Big Block!!!! To enjoy it and drive it too.... LS.
Stoked to see this awd conversion
I'd start at 25 degrees advance and lean out afrs to 12.5:1 maybe even 13:1 after 5krpm. You gotta git rid of that KR.
A good rule of thumb is on a NA motor you lose about 3% power per 1,000’ of density altitude. At your altitude you stand to lose 12-15% power compared to sea level on a standard day. That may be where the discrepancy in the 4.8’s expected power is coming from.
There used to be a saying ( No replacement for displacement) . So if apple's to apple's comparison. Big block should always win.
The quicker 0-60 with wheel spin tells me you need more gear.
Which with a 4.8 is a given anyway. 4.56s for the win
truck sure sounds awesome. I had a 4.8L sierra and it was a great reliable truck, and never had issues.
Sure cut up the air box, the restriction is the actual intake manifold. It is also hurting too end power by, I would bet at least 15hp..
I was thinking the same thing. His kpa is up then goes down then back up how is that in the air box or tube?? Lol it’s the intake. I have the same tube, box and filter and I’m at 98-101 kpa all day long at WOT of course that’s at sea level
On that filter box modification just wanted to mention it’s very common for bmw guys to do a “charcoal filter” delete. Idk if Chevy did this where they put an activated charcoal filter after the regular air filter, but if they did and you remove that you might be able to rid some of that restriction and maybe gain some throttle response. Did it on my e92 and I makes enough difference to notice
I really hope you don't go to a 6.0L or 6.2L, stick with the 4.8L and throw on a supercharger. I'd like to see the "cheap" mackdaddyparts Cadillac setup that Richard Holdener dyno'd or maybe whipple setup. Oh and port the heads which you really should have done while motor was apart.
That 500 Caddy is a torque monster.
Great content LT. I enjoyed that you stuck to your process and modded the 4.8 even if swapping in a 5.3 or 6.0 seems to make more sense.
Far as testing a good one is acceleration rate graph in HP tuners .
Gives the ability to see where it's accelerating good and where it may be lacking and you can adjust just areas of the tune in the weaker places .
Find if your shift point should be raised or lowered etc..
I've forgotten the pids and math it took to set it up but to give credit where it's due I got it from
Goat rope garage here on CZcams
Please 🙏 supercharge it I can't watch another turbo 😫build (not just you but everyone) 🇺🇲
If your going to stick with the 4.8 the only way to get it to shine is with a cam that’ll hold power out to 7500 or so rpm, get a good set of aftermarket heads and a good flowing intake. If your not turning that motor over 7000 rpm, then buy a 5.3/6.0 crank and rods, they’re the same. And swap it in. Then you’d have a slightly higher compression 5.3, and more power.
High altitude is definitely a challenge. I live in Colorado so I feel your pain.
Boker mermaid on the bench! This man knows what quality is
port and polish your heads, gasket matching the intake. spend some love on the heads. fan modulation for a slightly higher temperature. change final drive for more torque.
I had an 01 suburban with an 8.1. It was a strong running vehicle. It didn't have problems hauling the whole family and a heavy load
The stock 8.1 setup would be great for towing and you said it Best there is no replacement for displacement but the little 4.8 did great considering the displacement and you're turning the 4wd components I think it was a very good comparison because each trucks setup they'll have their place like ugly truck trailering the step side to the track
Using your correction factor of 17 percent that puts the little ls about 325hp, impressive for such a small engine
You have todo it above the level of the filter because you need filtered air going in. If the air is going under the filter it’s not getting filtered
Still cool. I’m building a 5.3 to a 5.7 so basically a iron block LS1, with a BTR Truck Norris cam and a TBSS intake.
I’m really interested in that cam
I don’t think putting a 5.3 in to replace a 4.8 would’ve been worth it, there isn’t much of a difference there, I definitely agree with a 6.0 bc that’s a totally different beast. I would love to lq9 swap mine.
A 5.3 makes like 10 more hp, definitely not worth it. A 6.0(lq4) 15 more than that.. we aren’t talking huge Gains in power.. the biggest difference is the torque and shift(lower) in the power band.
I'm building an LQ9 right now
@@matt6951 6.0 would be a pretty good jump, not only for the horsepower but the torque. I honestly would love to see the 4.8 get some love, but it's hard to not just go with the 5.3 or the 6.0 for around the same cost.
@@OGbqze 6.0s usually go for quite a bit more than 4.8s and 5.3s(which tend to be about the same on average) For whatever reason.. they are not, totally different beasts. They make marginally better power stock, not enough to justify the cost difference. I’ve had them all, 4.8, 5.3, 6.0, even a 6.2
@@RAWRMotorsports lq9 is the most desirable 6.0 imo, have fun with it!
We have a 5.3L '04 Silverado and it's ok, but my BoltEV doesn't care about altitude and does the 0-60 dash in just less than 6.5 seconds. Both serve their own purposes and we are keeping both....but most of the miles are run in the EV.
I think it was good testing with good results however had you started with a 5.3 I think the numbers would have been much better.
Personally I just like the 5.3, the 4.8 always seemed slightly lacking to me. Boost would obviously change that. Haha
only difference is dished pistons and wee bit more stroke
Lmao not much difference at all
Here's what I know the 5.3 starts out more hp and responds better to modifications.
If you don't think so, jump over to Richard holdner's channel and watch his 4.8 videos and 5.3 videos, he has many 5.3 builds that go over 500 chp but the 4.8 do not.
I have a 98 single cab stepside with a 8.1 and allison 1000 transmission , its flawless and love it. in my opinion the 8.1 is under rated . i would like to see more aftermarket performance parts out there.
you litterally murdered that airbox dude wtf
Would love to see a roots supercharger on that 4.8. I don't know if they're popular as turbocharging is so common, but I just love the sound of that little LS revving out. The 4.30s would be right at home, no doubt.
Install a couple of mini fans in the fender well at the openings for the fresh air and pull in the air in the filter box
Hey LT!
You are always putting out great content! Thank you!
I’m in the process of swapping my 94’ K1500 and was wondering about the dual 3” to single 4” exhaust and how it would sound. Then how convenient for me you are doing the same exact set up I’ve been building in my head! Haha.
Looking forward to the completed system with tail pipe!
Thanks again, Keep up the good work!
275hp is good for 4700/4800 feet. Thats close to 300hp at sea level. Intake and larger throttle body will be 10whp.
You should have enough subs to get a Maggy and or whipple at cost (assuming you advertise the blower on a few videos). Youd be suprised those companies work with youtubers/ social media builders more then youd think. Id email them the truck videos. See if they cant send u a new 2650 at their cost.
The most unfortunate part of this whole adventure is you didn't have a 8.1/Allison combo to begin with.
For anyone considering all of this adventure, a 6.0 covers all the bases. It has enough to it to make great torque, and it has all the LS support for HP.
The smaller LS are more affordable, ut not by much really.
The 8.1 is king of the tire roasting pure raw beast muscle though. Dyno numbers be damned, if you aren't old enough to remember driving old big block cars, it is impossible to explain the difference in driving experience.
I have a 8.1/ 80e in a 1/2 ton regular cab short bed 2wd. It is the closest thing I have ever driven to the 70s muscle cars. Even have roll up widows to complete the feel haha. I love it so damn much
Thank you for the great content and look forward to another year of it. Merry christmas LT. Claiming that hill to one mill!
K&N are not worth the money.
When it comes to filters and restriction, the total surface area of the filter is going to determine how much air it can let through. Some media is better then others, but just to start out with you should put the biggest filter you can fit under there to allow the most surface area. At some point the filter will flow more air then the tube can.
This comparison of data and thoughts/conclusions is really cool. But I’m honestly only here for one reason…what will he name the little 4.8?!? Lol. Only kidding about being here for one reason. These videos are great, LT! Your knowledge and research is top notch. Keep up the good work!!
Love what your doing, let em breathe, let em eat. Nice video. Thanks
My 00 Sierra BONESTOCK 4.8 single cab stepside 3.42 gears 2wd ran a best of 16.4 on the 1/4 at sealevel. I had done a tuneup prior to racetrack time. It had around 70k miles. Pretty slow in my opinion.
That timing revelation is interesting. Up here in the Boise area most LS' like between 24-26°
What’s the weight difference in these trucks? I’d be curious how much faster the SCSB truck would be with the “naturally aspirated” 8.1 like in the ugly truck.
i am half tempted to swap in my built 547 into the stepside lol... that would be so fun to do a 4 wheel burnout/launch
Unless you duct air from in front of the radiator cutting hole in the filter box may reduce horsepower.
Cold air intakes rarely add power they simply keep power by not having to pull timing etc because the intake is sucking in hot air
A must is an air intake temperature sensor and manifold temperature sensor that you can data log to see if the ECU is pulling timing to prevent knocking.
Neat comparison. Thank you for all the hard work.
This has been a fun comparison to watch. You should call it "the little engine that could". Keep up the great content!
Merry Christmas!
LS reluctor wheels are known to be as much as 14 degrees off. Id either verify timing with a light or keep adding until hpt shows knock
The Amazon 4" intake is what I'm using. But I have completely shrouded the filter from the engine and rad. Much better performance just sealing off from those 2 areas
Playing with timing on an na motor will not affect air flow. given throttle positions and rpms (assuming equal weather conditions) will result in the same maf readings for given rpms.
Love the background scenery in these road test videos
on the stock air box, the upper air intake can be removed, you can also remove the holding ring from the MAF and remove the screen.
Whoa that thing is slower than I expected
4.11S CONVERTER RAISE SHIFT POINTS AND REV LIMITER had caps lock on 2011 4.8 makes about 260hp to wheels stock with muffler and afe dry flow do all synthetic trans engine differential fluid aftermarket plug wires. If older 4.8 port polish throttle body.
I did not follow or understand your logic for using the MAF to determine engine power based on ignition timing... How is airflow through the motor affected by ignition timing? Both valves are closed when the spark goes off. Can someone explain to me what I'm missing? The only only possible thing I can think of is that by making more power with more advance you'd somehow gaid additional scavenging effects on the exhaust event which would possibly draw more air through the motor? That seems really hokey to me though because at perfect efficiency, the motor is an air pump, and knowing the cylinder volume, spinning the motor at any specific RPM will move X amount of volume of air through it... Valve timing could change things, but ignition timing, I'm not biting on that.
You added nice big holes more air, yes but your holes added hot underhood air, add power or lose power?
Sure the LS has a gate following but the mighty Big Bock has been here for a long long time kid, you wanna go fast ? there is still no replacement for displacement Big Block for the win !
Once a 4.8 has been pulled there is no sensible reason to put it back! 5.3s are ALMOST FREE! Literally, the only reason the 4.8 exists is so that Chevy could give the option to poor people and fleet managers. It cost them exactly the same to manufacture, they just purposely neuter it with half a crankshaft...
If you're not poor/fleet manager, a 4.8 has no reason to exist. It's like a 2WD Jeep. Or a 4 door Corvette.