@@keithharris9685 Definitely put it to the test. Those blocks are stronger than people think. I believe the 330 forged crank might have helped it survive being a more rigid crank than the stock cast unit. Gonna put a girdle on it this time tho, gonna turn up the wick. They are better engines than I thought. I used to only build 425s and 455s. That old 403 even took a 125 shot of nitrous and held together. Ring closed up and broke a piston. Ran real good for a minute.
Thanks for the video, brings back a lot of good memories. The factory compression on the 403 did suck, couldn't agree more. We did nothing more than change heads with small CC heads from a 330 and saw almost a 100 horse power with the stock cam. With the higher compression, you can run a better cam, and then start making real power. If you don't boost the compression in those, changing the cam is almost pointless. 100% right about the 403, keep it below 500 horsepower and 6000 RPM.. You start doing more than that, you need to do a lot of BS to the motor. At that point you're better off just building a chevy or some other motor. But they can make one hell of a daily driver with some extra street performance.
Back in the early 80's, I built a 403, trashing the smog/ low compression heads with #5 350 heads with .010 milled with big block large valves with Mondello Olds custom valve train & big hydraulic cam; modified Holley Street Dominator intake with heat cross overs blocked off; Hooker headers & early NOS 150 hp power shot system with both spray bar orifices opened up two drill sizes. That oversquare 403 would rpm to 6800 repeatedly, easily, and never had a problem with that engine.
I always wanted to try to fit a 455 crank in a 403 block for a cheap stroker. I know stock, a 403 was a torque monster. Id love to build one with some good heads, cam and compression. Best motor Oldsmobile ever put out. I just wish they didn't have tge windows above the mains.
@@inscoredbz DX 350 block will swallow up a 425 crank. 440 cubes is possible. Block practically indestructible. Has big block main journal diameter. Seen a few built, one was making 800hp NA.
@@thereluctantgearhead4544 anything good for an olds is had to find and expensive as hell. Always has been, but it's way worse now. Unless you buy some of those super awesome procomp olds heads lol
LS and LT new Chevy motors have windowed main webs too and no one says they are weak ! Has anyone ever seen a 403 fail in the bottom end ! Ive had 4 of them up to 650 HP stock bottom end never fails !
Ask Dick Miller, he's blown the crank out of a few of them. Making serious power too. He was turning serious Rpms with them too. He's done more R&D on 403s than probably anyone on the planet. But they will take more than most people think they will.
403 stock rods are the strongest SBO rods ever made from the factory. They are tough. Resized them with ARP bolts & I used a 1966 330 forged crank in mine with KB pistons. I gave it hell for years with no bottom end failure. Put a shot of nitrous on it and broke a ring land from not enough ring gap. So it was my fault it fucked up. But I was young and still figuring this shit out. Live and ya learn
@@thereluctantgearhead4544 yes I'm sure top end engines will find the limit , but true they take a lot more than people think , I have seen a 403 with welded up main webs in Australia, it worked and looked magic , they cooked the whole block in a kiln , .
I run a Olds 425 and 488 stroker in G bodys. I also have a 455 in a Studebaker Lark. Your 403 ran harder than my 488! My 488 has a 4.5 stroke 10.7:1 mahle pistons C heads with minor work on exhaust it has a howards cam .535 lift 227/235 281/289 109lsa. 3.42 gear. Love listening to your knowledge. My Lark has just a 1970 455 refreshed with a w30 4 spd cam I have ga heads on it hope to get at least 12.2 out of it on pump gas. My only run it blew through the converter and only ran 12.8 @ 101. I am going to soak up what you say and hope to run more respectible times.
Thanks for watching man. Gearing up to build a 455 with a 4.500 crank myself in the near future, those cranks are actually not real expensive. Seen one for $650 recently. I'm shooting for 700hp NA with it. 69 455 block. Also have a couple 425s. Real good engines. Way to get the big Oldsmobile engine to make big power is a big solid roller cam & alot of compression. I'm using a Super Victor intake with a 1050 Dominator on it. Probably port a pair of the import heads from Bernard Mondello. The 65-67 425 blocks are probably the strongest of the bigblock versions. 68-72 455s are cast with good iron too. I use oil restrictors in the mains too. Port the rear main cap, use a good windage tray and a 7-8 at oil pan. Open up the oil drain back holes too. Forged pistons and H-beams needed too. I've bent stock 455 rods. I turn them up 6800-7200 rpm.
I've had about 30 Cutlass's back in the day. 68 to 87. Always liked them. Had a 69 442 that was a monster. Ran high 10s with a C-headed 455 NA. Also ran a 79 Cutlass with about 7 425s and 455s went thru it. Built a NHRA G/Stock 455 for a 71 442 back about 30yrs ago. Also built a legal "Stock" 350 Olds too. Been a fan of Olds engines since the mid 80s. I hate to say it tho, I'm currently building a rowdy 496 bigblock Chevy for my 79 Cutlass. Just untill I get the monster Olds done. Olds parts get expensive. Paid $700+ bucks for that Super Victor 455 intake. Most expensive single 4 barrel intake I've ever bought.
I started with Pontiac engines, then Olds and Buicks, then I got into bigblock & smallblock Chevys for the price and parts availability. But I still dig my BOPs. Even built a 500 inch caddy back in the day for a buddy. It went into a 80 Malibu. It was basicly stock other than a Performer intake and mild cam. Ran like hell for what it was. Probably would have ran mid 12s. Limited parts availability on them Caddy engines back in the day. They make cool stuff for them now, but ya better have a bunch of money.
I like the 403’s. I built one a few years ago, basic stock bottom end with arp bolts, 7A (350 not 307) heads, Howard’s roller cam, and RPM manifold. Made pile of torque, perfect with 2.73 highway gears in my gbody. I have another one on an engine stand waiting for it’s turn at the machine shop, it’ll get flat tops with BBO heads this go around. SBO heads bump up the compression but the motor is trying to breathe through a straw.
Believe KB still sells the 6cc flattop pistons for them. Works out nice with 455 heads. I just used a pair of milled J heads off a 73 455. Ground the bumps out of the exhaust ports, converted it to adjustable valvetrain and ran a 245@.050, 540 lift 108 LS Lunati cam. Ole 403 ran pretty damn good. I'm gonna build it again. Probably gonna use a pair of 1966 B heads off a 425 Toro I have sitting around. Going to tap them for 7/16 studs & 3/8 pushrod guideplates. Also gonna go with the Super Victor intake and a healthy solid roller in the 260@.050 range.. Going with a girdle & studs on this build. 330 forged crank, prepped 403 rods with ARP bolts and the KB flat tops.
@@thereluctantgearhead4544 that’s good stuff man. Everyone laughs at J heads (j is for junk! 🥴) but like you said, simple mods and they’re much better. Looking forward to this build!! There’s a few guys out there making a ton of power with 403’s, Mark Remmel and a guy named Dr Dan come to mind. I think Remmel makes a girdle too. Oh I forgot to mention I filled the exhaust cross overs and the exhaust center divider. Those changes along with the 4/7 swap cam, it didn’t have that distinctive Olds burble anymore lol
@@jimmy_olds Ole Bill Trovoto builds some serious Olds engines. Seen a 403 Dick Miller built make over 600hp turning 7500rpm. Yep the old J heads ain't the best, but they flow alot more than the smallblock heads and with alittle work they are useable. People practically give them away too, so ya dont feel bad about drilling them for the 1/2 inch head bolts. I have a few pairs of C heads, also G, Ga, E and B heads in stock. But most of them will go on 455s and 425s, so I'd hate to drill them out. I have a collection of Oldsmobile engines and parts I've stashed away for decades. Was pretty hardcore Oldsmobile back in the day. Parts for them just got too rare and too damn expensive and it pushed me to build Chevy engines. I actually started with Pontiac engines back in the early 80s. But people sell that shit like it's made out of gold now. Used to buy Pontiac 455s for $50 bucks. Bought a RAM AIR 4 400 for $150 bucks out of a 70 Formula firebird. Shit like that was pretty easy to find 40+yrs ago in junkyards. Alot of musclecars got totaled and scrapped. They were just used cars back then. I still like the old Ponchos, but I can't afford the ones I want anymore. 69 GTOs bring big bucks these days. Them old Pontiac engines had a distinct sound. I still have a 63 SD421 Catalina I need to restore. Original engine was grenaded back in 1970, so it's getting a stroker 467ci 400 engine. Has a 4spd and 4-30 Safe-T-Trac rearend. Gonna swap a Super T-10 with a Lakewood bellhousing in place of the original T-10. Been collecting parts for it forever it seems. One day it'll run again. Good way to go broke is to build some Pontiacs from the musclecar era. I've had some good ones.
@@thereluctantgearhead4544 ole Bill Travato, every Olds guy needs his book! My buddy is a Pontiac guy, he’s got some wild shit. Ram Air 5 heads maybe? The intake runners are so damn big there is a push rod tube in the middle of them. He’s always trying to get me to build one, but Olds are expensive enough! Lol. Speaking of expensive, I’m building my first big block Chevy now, holy F they’re expensive.
@@jimmy_olds Yep that Pontiac shit is expensive as hell. Have a buddy that runs a Superstock SD455 engine in a 87 Firebird. Runs in the SS/GT class. Runs low 9s with a Q-jet & original iron heads. He's got a shitload of money tied up in that thing. Makes 725hp at 8000+rpm. It's a monster. Has about .950 lift solid roller in it. I build alot of bigblock Chevys myself. Hard to beat them big bastards. I'm building a 454 now and hating to spend the $1200 bucks on a cam & lifters. Shits gotten crazy high. Also building a 496 that should make 800+hp NA and a 439ci twin turbo unit to go no prep drag racing with. Also have a shitload of rowdy SBCs too. Power per dollar, they are hard to beat. With today's heads and shit, pretty easy to build a 550+hp NA SBC. Parts availability for them is better than anything made. Cheap too. But ain't none of this shit really cheap anymore. Did buy a pair of new Brodix 200cc heads set up for a roller cam, paid around $1500 for the pair. Can't buy a pair of aluminum heads for a Pontiac for less than $2500-$3000 bucks. Aluminum RA5 heads are $10,000 a pair, but they come with a nice intake. And good aluminum Olds heads are real hard to find and even harder to pay for. The old Batton heads flowed pretty good, but the Bulldog heads were the ultimate Olds head. But them things cost a fortune and impossible to find. I remember a guy back in the mid 90s running Bulldog heads on a 441ci 350 DX build, it was over 850+hp NA and ran mid 9s in a full weight 70 442 Cutlass on 28x10.5x15 meats. It was a NMCA " Real Street" class car. It was serious as hell. Don't know what happened to the Bulldog company tho. Guess there wasent enough people that could afford them. They also made the best bigblock Cadillac heads ever cast. Big bucks tho. Probably didn't sell many of them.
It's funny the very rare NASCAR Olds block is made with solid very thick mains , 4 bolt mains , and the 403 ci bore of 4.351 inches , imagin the stroke you would have needed to get to NASCAR's 358 ci limit ! It would have been a rev machine compared to the Ford's and Chevy counterparts !
I remember seeing a NASCAR 358ci Oldsmobile engine back about 40+yrs ago. It made around 585hp NA at around 8500rpm. Used heavily ported Batton heads and a rare as hell Victor intake made to fit those Batton heads. Pretty serious SBO for 1981. In the mid 90s, there was a dude with a orange 71 442 that ran in NMCA "Real Street" class. It had a DX block SBO of around 440ci, it was making 800+hp NA with Bulldog heads & intake, heads flowed well over 400cfm, 15-1 compression and a 850+ lift, 290+@.050 solid roller. Think it ran low 9s high 8s on 28x10.5x15 slicks. Pretty hardcore for the day. Those SBO engines have potential. Shit gets expensive tho.
@@thereluctantgearhead4544 it just the very big potential of that massive bore and super short stroke , Charles F Kettering who designed the Olds engine from the start had the best ideas , that Olds 86 mm stroke is in the new Ford Coyote engine and the new 5.5 GM DOHC motor and Lamborghini, along with so many Japanese motors ! He was spot on !
@@thereluctantgearhead4544 yes the Olds diesel was what the 403 should have been , but the 403 came just too late , if it was there in 1967 instead of 1977 it would have been a power house , think if it with DOHC and the rest ! I'm in Australia and our 253ci , 308 ci and 355 ci Aussie only motors were designed around the Olds in 1969 same port locations , but chev bore spacings , same valve rockers , same 6 degree valve angles , it evolved to a injected 5.0 and 5.9 in 1988 , it has the same manifold as a LS same port location as an LS but we got it in 1988, ! Look it up , GM Holden Australia wanted to go Over Head Cam in 1990 , and produced 250 engines , look it up 5.0 litre GM Holden V8 , there are many pictures , but GM USA refused to pay !
While they may not be built as robust as the tall decks blocks (400,425,455) these make for a nice upgrade if you got a car that's set up for a low deck olds(260,307,350) because it will bolt right in with no mods, exhaust manifolds and accessory brackets swap right over. So if you got a clean 80s gbody with a 307 or 260, you can shove a stock 403 right in and make it look 100% factory and will run way better.
My 79 Cutlass came with the 260, I swapped it out for this 403, then I went to the 425 & 455s. But that old 403 ran better than most people need. It would run low 12s in the 1/4 and was a daily driver. Mpg wasent bad either. Think it got 15-18 mpg.
@@thereluctantgearhead4544 for me the biggest plus is that it's a 100% bolt in, so you can keep all your existing accessories like power steering and air conditioning from your 260,307,350 and even in stock form the 403s will run pretty decent especially if you throw a good exhaust on it and eliminate a lot of the smog stuff.
Bore/stroke combo is quite similar to Mopar big block low deck 383/400…really similar to the 400. Great rod ratio. Too bad the windowed mains compromise main strength
Yep, they had the right idea, but that block was the weak point. Those low deck Mopar B engine blocks will take alot more power than these 403s will. The old 383 B engines had a nice forged crank and stout rods too. Best thing to do with those 400s is swap a forged 440 crank into it or an aftermarket crank with more stroke. Those Mopar parts are pretty expensive too. Similar to Oldsmobile prices. Shit adds up quick.
@@thereluctantgearhead4544 that’s for sure! Love the 440 source heads on my 383. I’ve got a zero deck engine from the factory. It loves those closed chamber heads. 135k on the short block.
@@derwinrandle2682 Sorry if your offended, but I'm really an angry dude and it helps me release pressure. Don't believe in censorship either, I might not like what someone else says, for example religious jargon, I'm actually an atheist ethnic Jew, but I don't concern myself with such matters. So people can say or believe whatever they want as long as it doesn't physically harm me, then I go into full defense mode. Live and let live is my motto. And don't let "bad" words be your primary focus, it's just sounds emmiting from my vocal cords. Nothing to fear. Most real mechanics cuss like sailors. That's just the nature of the extremely aggravating environment a mechanic exist in for decades. Shit gets old for sure and it makes one become bitter. Hard life for sure. Thanks for watching brother.
There use to be a rumor that the 403 engines earmarked for the station wagons with the tow package got a 403 block that didn't have windowed mains. Not sure how true that is but if it is true I sure would love to find one of those! Or maybe weld the windows closed on what can be found? With a standard bore and a 455 crank you could get 505.5296 cid out of a 403 block! Would have to cut the crank throws down an grind the mains down and the longest rod you could use would be 6.205" with pistons that have a 1.00" compression distance, a little sketchy but doable. That is if the bore is long enough? Seeing how the rod journals are 2.500" in diameter, the crank could be destroked .150" and ground down to 2.200" to use big block chevy 6.200" rods so the pistons can be .075" taller.
Yeah I've heard about the elusive solid main block for many years, but it seems nobody has ever seen one. A guy gonna build a Oldsmobile racing engine should use the DX 350 blocks with a forged 425 crank offset ground to a 4.00 stroke. Pistons for it will cost a fortune.
Allegedly there were a few tow package Trans And built with the solid block, but nobody has been able to produce one. I looked for one back 30+yrs ago, they were non existent even back then. I pulled this one because it was in a 77 TA and everybody back then was saying that's were you would most likely find one. But I stripped it down and turned out it was windowed. Was dissapointed, but said fuck it and just built the thing. I bought 4 more 403s years ago and they all had windowed blocks, so I pretty much gave up on the Holy grail. A 500+cube SBO would be cool. It would have to make a shitload of power. Pistons in these fuckers are huge. Some heads with 2.30/1.88 valves would definitely help. Olds heads are valve limited by design.
The 403 connecting rods are the strongest SBO rods from the factory strangely enough. But they are thicker in critical areas compared to all other factory SBO rods. The 330 forged cranks are the best stock SBO crank. Bolt right in, but gotta use the 330 damper and flexplate. Stiffer crank in these windowed blocks helps them live longer. Cast cranks flex more under load and can distort the mains. 330 crank is stiffer and moves around less. They are getting rare these days tho. I bought a running 66 330 for $100 bucks to use the crank. That was 30+yrs ago tho. I'm sure they cost alot more now.
Those 330s are actually damn good engines to build. I built one for a dude years ago that ran 6.90s in the 8th in a 84 Cutlass. It was rowdy, big 268/272@.050 solid roller and 12.75-1 compression. Ported & milled C -heads with a Victor intake. Bored it to a standard 350 Olds bore and used JE pistons for a 350. It had 403 rods that were prepped with ARP bolts. Beams polished & shit. It turned 7500+rpm everytime it ran. Made over 500+hp.
@@thereluctantgearhead4544 Did you know you can do a stroker with your short deck Olds? You can have your factory crank offset ground for about .265" extra stroke if it's a virgin crank. Get a set of eBay used Nascar 6.200" rods and a set of AutoTec customizable 4032 forged pistons. Would probably need to center the rod at the small end though because most of those rods are .900" thick at the big end and the others just get thinner from there. Not a big deal though. And just so you know, the rod journal diameter would have to be ground down to is 1.850" to get that stroke. Or you can get the 1.889" diameter big end Nascar take out rods if the 1.850" scares you? Have done this to small block Buick 350s to get an extra 20 cubes. That 403 can be a 437 cid with the extra stroke. Weld or braze some mild steel or if you can get cast iron plate the right thickness would be even better and you'd be styling! Perhaps a halo girdle as well? Finishline Performance in Hastings Michigan built a sbb 370 stroker with 1.850" journal diameter Nascar take out rods and supercharged it to 750 HP! The thing was an animal, the last I heard of it is it broke a th400 and his kid went to college.(his son's car) That was about 10 to 15 years ago. 😎
Is the part of the web around the "window" hole thinner than the web on the older non holed blocks? Compared to the mid 1960s 330 engine? I understand some Olds 350s had the holed webs?
Yep, the old blocks are thicker and stronger. 330 is a real good block. Early 350s are too. In 1977, Oldsmobile made all the SBO engines with windowed mains and they are weaker than the old blocks. The diesel 350 DX is the best Oldsmobile block among the small block versions. I wouldn't want to push a windowed block past 500 hp or so. But people like Dick Miller have gotten NA 403s past 600 hp. Wouldn't do it long tho. Probably 8th mile be best. They make girdles and main caps for them that add much strength. Head studs a good idea under heavy use too.
Also used studs, guideplates & adjustable roller rockers. Pretty much mandatory with a Olds engine with a big cam. Stock valvetrain limited to .500 lift or so.
You said at the end was getting hard to find that starting to be everything in our world bro it all got scrapped and turned into a Honda 😂and quality control doesn't exist anymore
KB 405 .024 Pistons are still available. For my 1979 "Bandit" Y84 Trans Am, 2.73 rear End, AT, ..."One of these days", I would like to "Soup Up" (I'm Old School) it's 403. I want to maintain, at least in appearance, ALL SMOG equipment, AC, etc. I'm thinking KB405 .024 pistons, , MILD Cam (power from idle up or 1000 RPM up) Mild port and polish on the STOCK heads, Recurve the stock HEI distributer, re-jet the stock Rochester Quadrajet 4V carb. Maybe replace the stock exhaust "Y pipe" with a true, two into one, Y Pipe, flowing to the single, Aftermarket High flow cat. This for weekend street use. Comments please.
The old W-30 cams work pretty good for a mild driver. Headers and dual exhaust definitely help. A old stock 330 or 350 intake non EGR from the late 60s would help. Q-jet from early 70s 455 would work alittle better too.
Yep, and a shitty replacement at that. But the late 70s was a pretty grim time for factory muscle. But they do have potential to be a good hipo street engine.
There are some nice bottom end girdles available, but under 500hp or so it's not really nescesary. I was nervous about it when I first built the thing, but after driving it daily for 2yrs and running it at the track on a few occasions giving it serious hell, the bottom end never came apart. I wouldn't want to go any further with it without a girdle & o-rings tho. 6000 grand and under its pretty safe. Definitely not the best choice Oldsmobile engine for a all out effort. But they do make good street machine engines.
Looks fragile as hell for sure. I figured it would come apart when I took it to the track. But surprisingly it held together. Even played with a small shot of nitrous and ended up breaking a piston ring land doing nitrous burnouts on back roads for distance. That's when it got taken apart the last time. 30+yrs ago.
Had a 79 Ta with a 403 in highschool. Even with the 2:43 rear, it would run a 14.7 in the quarter. Love the Ta's
Definitely some of the best looking cars ever built. Smokey and the Bandit made me a fan.
I think you the kind of fellow who will challenge and see if those mains are up for task. I think you really wanted to blow it up.
@@keithharris9685 Definitely put it to the test. Those blocks are stronger than people think. I believe the 330 forged crank might have helped it survive being a more rigid crank than the stock cast unit. Gonna put a girdle on it this time tho, gonna turn up the wick. They are better engines than I thought. I used to only build 425s and 455s. That old 403 even took a 125 shot of nitrous and held together. Ring closed up and broke a piston. Ran real good for a minute.
Thanks for the video, brings back a lot of good memories. The factory compression on the 403 did suck, couldn't agree more. We did nothing more than change heads with small CC heads from a 330 and saw almost a 100 horse power with the stock cam. With the higher compression, you can run a better cam, and then start making real power. If you don't boost the compression in those, changing the cam is almost pointless.
100% right about the 403, keep it below 500 horsepower and 6000 RPM.. You start doing more than that, you need to do a lot of BS to the motor. At that point you're better off just building a chevy or some other motor. But they can make one hell of a daily driver with some extra street performance.
Good swap for 260 and 307 powered cars. Hell of a difference.
Back in the early 80's, I built a 403, trashing the smog/ low compression heads with #5 350 heads with .010 milled with big block large valves with Mondello Olds custom valve train & big hydraulic cam; modified Holley Street Dominator intake with heat cross overs blocked off; Hooker headers & early NOS 150 hp power shot system with both spray bar orifices opened up two drill sizes. That oversquare 403 would rpm to 6800 repeatedly, easily, and never had a problem with that engine.
I always wanted to try to fit a 455 crank in a 403 block for a cheap stroker. I know stock, a 403 was a torque monster. Id love to build one with some good heads, cam and compression. Best motor Oldsmobile ever put out. I just wish they didn't have tge windows above the mains.
doesnt have space for that one but u can put olds 425 crank and put it on a lathe and make it work and makes 472ci there are some builds how to do so
@@inscoredbz DX 350 block will swallow up a 425 crank. 440 cubes is possible. Block practically indestructible. Has big block main journal diameter. Seen a few built, one was making 800hp NA.
@@inscoredbz Better have a fat wallet to build a 800+hp NA Olds tho. And the Bulldog heads & intake needed are impossible to find these days.
@@thereluctantgearhead4544 anything good for an olds is had to find and expensive as hell. Always has been, but it's way worse now. Unless you buy some of those super awesome procomp olds heads lol
LS and LT new Chevy motors have windowed main webs too and no one says they are weak ! Has anyone ever seen a 403 fail in the bottom end ! Ive had 4 of them up to 650 HP stock bottom end never fails !
Ask Dick Miller, he's blown the crank out of a few of them. Making serious power too. He was turning serious Rpms with them too. He's done more R&D on 403s than probably anyone on the planet. But they will take more than most people think they will.
403 stock rods are the strongest SBO rods ever made from the factory. They are tough. Resized them with ARP bolts & I used a 1966 330 forged crank in mine with KB pistons. I gave it hell for years with no bottom end failure. Put a shot of nitrous on it and broke a ring land from not enough ring gap. So it was my fault it fucked up. But I was young and still figuring this shit out. Live and ya learn
@@thereluctantgearhead4544 I agree , and well said !
@@thereluctantgearhead4544 yes I'm sure top end engines will find the limit , but true they take a lot more than people think , I have seen a 403 with welded up main webs in Australia, it worked and looked magic , they cooked the whole block in a kiln , .
Cant say that about the 455, that long stroke motor will toss a rod fast!.. Seem many windowed 455 blocks..
I run a Olds 425 and 488 stroker in G bodys. I also have a 455 in a Studebaker Lark. Your 403 ran harder than my 488! My 488 has a 4.5 stroke 10.7:1 mahle pistons C heads with minor work on exhaust it has a howards cam .535 lift 227/235 281/289 109lsa. 3.42 gear. Love listening to your knowledge. My Lark has just a 1970 455 refreshed with a w30 4 spd cam I have ga heads on it hope to get at least 12.2 out of it on pump gas. My only run it blew through the converter and only ran 12.8 @ 101. I am going to soak up what you say and hope to run more respectible times.
Thanks for watching man. Gearing up to build a 455 with a 4.500 crank myself in the near future, those cranks are actually not real expensive. Seen one for $650 recently. I'm shooting for 700hp NA with it. 69 455 block. Also have a couple 425s. Real good engines. Way to get the big Oldsmobile engine to make big power is a big solid roller cam & alot of compression. I'm using a Super Victor intake with a 1050 Dominator on it. Probably port a pair of the import heads from Bernard Mondello. The 65-67 425 blocks are probably the strongest of the bigblock versions. 68-72 455s are cast with good iron too. I use oil restrictors in the mains too. Port the rear main cap, use a good windage tray and a 7-8 at oil pan. Open up the oil drain back holes too. Forged pistons and H-beams needed too. I've bent stock 455 rods. I turn them up 6800-7200 rpm.
I've had about 30 Cutlass's back in the day. 68 to 87. Always liked them. Had a 69 442 that was a monster. Ran high 10s with a C-headed 455 NA. Also ran a 79 Cutlass with about 7 425s and 455s went thru it. Built a NHRA G/Stock 455 for a 71 442 back about 30yrs ago. Also built a legal "Stock" 350 Olds too. Been a fan of Olds engines since the mid 80s. I hate to say it tho, I'm currently building a rowdy 496 bigblock Chevy for my 79 Cutlass. Just untill I get the monster Olds done. Olds parts get expensive. Paid $700+ bucks for that Super Victor 455 intake. Most expensive single 4 barrel intake I've ever bought.
I started with Pontiac engines, then Olds and Buicks, then I got into bigblock & smallblock Chevys for the price and parts availability. But I still dig my BOPs. Even built a 500 inch caddy back in the day for a buddy. It went into a 80 Malibu. It was basicly stock other than a Performer intake and mild cam. Ran like hell for what it was. Probably would have ran mid 12s. Limited parts availability on them Caddy engines back in the day. They make cool stuff for them now, but ya better have a bunch of money.
@@thereluctantgearhead4544 I told my buddys about your channel we are all subbed to you!
@@wildrosegarage4208 Thanks man.
I like the 403’s. I built one a few years ago, basic stock bottom end with arp bolts, 7A (350 not 307) heads, Howard’s roller cam, and RPM manifold. Made pile of torque, perfect with 2.73 highway gears in my gbody. I have another one on an engine stand waiting for it’s turn at the machine shop, it’ll get flat tops with BBO heads this go around. SBO heads bump up the compression but the motor is trying to breathe through a straw.
Believe KB still sells the 6cc flattop pistons for them. Works out nice with 455 heads. I just used a pair of milled J heads off a 73 455. Ground the bumps out of the exhaust ports, converted it to adjustable valvetrain and ran a 245@.050, 540 lift 108 LS Lunati cam. Ole 403 ran pretty damn good. I'm gonna build it again. Probably gonna use a pair of 1966 B heads off a 425 Toro I have sitting around. Going to tap them for 7/16 studs & 3/8 pushrod guideplates. Also gonna go with the Super Victor intake and a healthy solid roller in the 260@.050 range.. Going with a girdle & studs on this build. 330 forged crank, prepped 403 rods with ARP bolts and the KB flat tops.
@@thereluctantgearhead4544 that’s good stuff man. Everyone laughs at J heads (j is for junk! 🥴) but like you said, simple mods and they’re much better. Looking forward to this build!! There’s a few guys out there making a ton of power with 403’s, Mark Remmel and a guy named Dr Dan come to mind. I think Remmel makes a girdle too.
Oh I forgot to mention I filled the exhaust cross overs and the exhaust center divider. Those changes along with the 4/7 swap cam, it didn’t have that distinctive Olds burble anymore lol
@@jimmy_olds Ole Bill Trovoto builds some serious Olds engines. Seen a 403 Dick Miller built make over 600hp turning 7500rpm. Yep the old J heads ain't the best, but they flow alot more than the smallblock heads and with alittle work they are useable. People practically give them away too, so ya dont feel bad about drilling them for the 1/2 inch head bolts. I have a few pairs of C heads, also G, Ga, E and B heads in stock. But most of them will go on 455s and 425s, so I'd hate to drill them out. I have a collection of Oldsmobile engines and parts I've stashed away for decades. Was pretty hardcore Oldsmobile back in the day. Parts for them just got too rare and too damn expensive and it pushed me to build Chevy engines. I actually started with Pontiac engines back in the early 80s. But people sell that shit like it's made out of gold now. Used to buy Pontiac 455s for $50 bucks. Bought a RAM AIR 4 400 for $150 bucks out of a 70 Formula firebird. Shit like that was pretty easy to find 40+yrs ago in junkyards. Alot of musclecars got totaled and scrapped. They were just used cars back then. I still like the old Ponchos, but I can't afford the ones I want anymore. 69 GTOs bring big bucks these days. Them old Pontiac engines had a distinct sound. I still have a 63 SD421 Catalina I need to restore. Original engine was grenaded back in 1970, so it's getting a stroker 467ci 400 engine. Has a 4spd and 4-30 Safe-T-Trac rearend. Gonna swap a Super T-10 with a Lakewood bellhousing in place of the original T-10. Been collecting parts for it forever it seems. One day it'll run again. Good way to go broke is to build some Pontiacs from the musclecar era. I've had some good ones.
@@thereluctantgearhead4544 ole Bill Travato, every Olds guy needs his book! My buddy is a Pontiac guy, he’s got some wild shit. Ram Air 5 heads maybe? The intake runners are so damn big there is a push rod tube in the middle of them. He’s always trying to get me to build one, but Olds are expensive enough! Lol. Speaking of expensive, I’m building my first big block Chevy now, holy F they’re expensive.
@@jimmy_olds Yep that Pontiac shit is expensive as hell. Have a buddy that runs a Superstock SD455 engine in a 87 Firebird. Runs in the SS/GT class. Runs low 9s with a Q-jet & original iron heads. He's got a shitload of money tied up in that thing. Makes 725hp at 8000+rpm. It's a monster. Has about .950 lift solid roller in it. I build alot of bigblock Chevys myself. Hard to beat them big bastards. I'm building a 454 now and hating to spend the $1200 bucks on a cam & lifters. Shits gotten crazy high. Also building a 496 that should make 800+hp NA and a 439ci twin turbo unit to go no prep drag racing with. Also have a shitload of rowdy SBCs too. Power per dollar, they are hard to beat. With today's heads and shit, pretty easy to build a 550+hp NA SBC. Parts availability for them is better than anything made. Cheap too. But ain't none of this shit really cheap anymore. Did buy a pair of new Brodix 200cc heads set up for a roller cam, paid around $1500 for the pair. Can't buy a pair of aluminum heads for a Pontiac for less than $2500-$3000 bucks. Aluminum RA5 heads are $10,000 a pair, but they come with a nice intake. And good aluminum Olds heads are real hard to find and even harder to pay for. The old Batton heads flowed pretty good, but the Bulldog heads were the ultimate Olds head. But them things cost a fortune and impossible to find. I remember a guy back in the mid 90s running Bulldog heads on a 441ci 350 DX build, it was over 850+hp NA and ran mid 9s in a full weight 70 442 Cutlass on 28x10.5x15 meats. It was a NMCA " Real Street" class car. It was serious as hell. Don't know what happened to the Bulldog company tho. Guess there wasent enough people that could afford them. They also made the best bigblock Cadillac heads ever cast. Big bucks tho. Probably didn't sell many of them.
2 weeks ago I bought a 78 Toronado with 70k miles on it, its as loud as it is slow. So definitely wanting to do a few things to it
It's funny the very rare NASCAR Olds block is made with solid very thick mains , 4 bolt mains , and the 403 ci bore of 4.351 inches , imagin the stroke you would have needed to get to NASCAR's 358 ci limit ! It would have been a rev machine compared to the Ford's and Chevy counterparts !
I remember seeing a NASCAR 358ci Oldsmobile engine back about 40+yrs ago. It made around 585hp NA at around 8500rpm. Used heavily ported Batton heads and a rare as hell Victor intake made to fit those Batton heads. Pretty serious SBO for 1981. In the mid 90s, there was a dude with a orange 71 442 that ran in NMCA "Real Street" class. It had a DX block SBO of around 440ci, it was making 800+hp NA with Bulldog heads & intake, heads flowed well over 400cfm, 15-1 compression and a 850+ lift, 290+@.050 solid roller. Think it ran low 9s high 8s on 28x10.5x15 slicks. Pretty hardcore for the day. Those SBO engines have potential. Shit gets expensive tho.
@@thereluctantgearhead4544 it just the very big potential of that massive bore and super short stroke , Charles F Kettering who designed the Olds engine from the start had the best ideas , that Olds 86 mm stroke is in the new Ford Coyote engine and the new 5.5 GM DOHC motor and Lamborghini, along with so many Japanese motors ! He was spot on !
@@thereluctantgearhead4544 yes the Olds diesel was what the 403 should have been , but the 403 came just too late , if it was there in 1967 instead of 1977 it would have been a power house , think if it with DOHC and the rest ! I'm in Australia and our 253ci , 308 ci and 355 ci Aussie only motors were designed around the Olds in 1969 same port locations , but chev bore spacings , same valve rockers , same 6 degree valve angles , it evolved to a injected 5.0 and 5.9 in 1988 , it has the same manifold as a LS same port location as an LS but we got it in 1988, ! Look it up , GM Holden Australia wanted to go Over Head Cam in 1990 , and produced 250 engines , look it up 5.0 litre GM Holden V8 , there are many pictures , but GM USA refused to pay !
Thank You for your Knowledge on these. 👍🏽
No problem man. Good luck with your build. Thanks for watching.
While they may not be built as robust as the tall decks blocks (400,425,455) these make for a nice upgrade if you got a car that's set up for a low deck olds(260,307,350) because it will bolt right in with no mods, exhaust manifolds and accessory brackets swap right over. So if you got a clean 80s gbody with a 307 or 260, you can shove a stock 403 right in and make it look 100% factory and will run way better.
Yep, damn good street engine for a G-body. Just gotta know the limitations.
My 79 Cutlass came with the 260, I swapped it out for this 403, then I went to the 425 & 455s. But that old 403 ran better than most people need. It would run low 12s in the 1/4 and was a daily driver. Mpg wasent bad either. Think it got 15-18 mpg.
@@thereluctantgearhead4544 for me the biggest plus is that it's a 100% bolt in, so you can keep all your existing accessories like power steering and air conditioning from your 260,307,350 and even in stock form the 403s will run pretty decent especially if you throw a good exhaust on it and eliminate a lot of the smog stuff.
@@briang4470 Yep, should have been a factory option.
Bore/stroke combo is quite similar to Mopar big block low deck 383/400…really similar to the 400. Great rod ratio. Too bad the windowed mains compromise main strength
Yep, they had the right idea, but that block was the weak point. Those low deck Mopar B engine blocks will take alot more power than these 403s will. The old 383 B engines had a nice forged crank and stout rods too. Best thing to do with those 400s is swap a forged 440 crank into it or an aftermarket crank with more stroke. Those Mopar parts are pretty expensive too. Similar to Oldsmobile prices. Shit adds up quick.
@@thereluctantgearhead4544 that’s for sure! Love the 440 source heads on my 383. I’ve got a zero deck engine from the factory. It loves those closed chamber heads. 135k on the short block.
Nice like your videos man you have a lot of knowledge!!
Thanks man
Great video only disappointed with all the cursing ,God’s blessings to you and all your family and friends my brother 🙏🏼
@@derwinrandle2682 Sorry if your offended, but I'm really an angry dude and it helps me release pressure. Don't believe in censorship either, I might not like what someone else says, for example religious jargon, I'm actually an atheist ethnic Jew, but I don't concern myself with such matters. So people can say or believe whatever they want as long as it doesn't physically harm me, then I go into full defense mode. Live and let live is my motto. And don't let "bad" words be your primary focus, it's just sounds emmiting from my vocal cords. Nothing to fear. Most real mechanics cuss like sailors. That's just the nature of the extremely aggravating environment a mechanic exist in for decades. Shit gets old for sure and it makes one become bitter. Hard life for sure. Thanks for watching brother.
You're talking about the KB405 pistons correct? Believe they're still made...may be time to put it back together
Yep, still available.
Is it possible to put a plate in the webs and weld up?
I've heard of people trying it, but never heard how long it would last.
probably create more weaknesses than you'd strengthen
A girdle and studs will help alot. Seen them over 600hp with a girdle and HardBlocked to the bottom of the waterpump holes.
There use to be a rumor that the 403 engines earmarked for the station wagons with the tow package got a 403 block that didn't have windowed mains. Not sure how true that is but if it is true I sure would love to find one of those! Or maybe weld the windows closed on what can be found?
With a standard bore and a 455 crank you could get 505.5296 cid out of a 403 block! Would have to cut the crank throws down an grind the mains down and the longest rod you could use would be 6.205" with pistons that have a 1.00" compression distance, a little sketchy but doable. That is if the bore is long enough?
Seeing how the rod journals are 2.500" in diameter, the crank could be destroked .150" and ground down to 2.200" to use big block chevy 6.200" rods so the pistons can be .075" taller.
Yeah I've heard about the elusive solid main block for many years, but it seems nobody has ever seen one. A guy gonna build a Oldsmobile racing engine should use the DX 350 blocks with a forged 425 crank offset ground to a 4.00 stroke. Pistons for it will cost a fortune.
Allegedly there were a few tow package Trans And built with the solid block, but nobody has been able to produce one. I looked for one back 30+yrs ago, they were non existent even back then. I pulled this one because it was in a 77 TA and everybody back then was saying that's were you would most likely find one. But I stripped it down and turned out it was windowed. Was dissapointed, but said fuck it and just built the thing. I bought 4 more 403s years ago and they all had windowed blocks, so I pretty much gave up on the Holy grail. A 500+cube SBO would be cool. It would have to make a shitload of power. Pistons in these fuckers are huge. Some heads with 2.30/1.88 valves would definitely help. Olds heads are valve limited by design.
The 403 connecting rods are the strongest SBO rods from the factory strangely enough. But they are thicker in critical areas compared to all other factory SBO rods. The 330 forged cranks are the best stock SBO crank. Bolt right in, but gotta use the 330 damper and flexplate. Stiffer crank in these windowed blocks helps them live longer. Cast cranks flex more under load and can distort the mains. 330 crank is stiffer and moves around less. They are getting rare these days tho. I bought a running 66 330 for $100 bucks to use the crank. That was 30+yrs ago tho. I'm sure they cost alot more now.
Those 330s are actually damn good engines to build. I built one for a dude years ago that ran 6.90s in the 8th in a 84 Cutlass. It was rowdy, big 268/272@.050 solid roller and 12.75-1 compression. Ported & milled C -heads with a Victor intake. Bored it to a standard 350 Olds bore and used JE pistons for a 350. It had 403 rods that were prepped with ARP bolts. Beams polished & shit. It turned 7500+rpm everytime it ran. Made over 500+hp.
@@thereluctantgearhead4544
Did you know you can do a stroker with your short deck Olds? You can have your factory crank offset ground for about .265" extra stroke if it's a virgin crank. Get a set of eBay used Nascar 6.200" rods and a set of AutoTec customizable 4032 forged pistons.
Would probably need to center the rod at the small end though because most of those rods are .900" thick at the big end and the others just get thinner from there. Not a big deal though. And just so you know, the rod journal diameter would have to be ground down to is 1.850" to get that stroke. Or you can get the 1.889" diameter big end Nascar take out rods if the 1.850" scares you?
Have done this to small block Buick 350s to get an extra 20 cubes. That 403 can be a 437 cid with the extra stroke. Weld or braze some mild steel or if you can get cast iron plate the right thickness would be even better and you'd be styling! Perhaps a halo girdle as well?
Finishline Performance in Hastings Michigan built a sbb 370 stroker with 1.850" journal diameter Nascar take out rods and supercharged it to 750 HP! The thing was an animal, the last I heard of it is it broke a th400 and his kid went to college.(his son's car) That was about 10 to 15 years ago. 😎
Is the part of the web around the "window" hole thinner than the web on the older non holed blocks? Compared to the mid 1960s 330 engine? I understand some Olds 350s had the holed webs?
Yep, the old blocks are thicker and stronger. 330 is a real good block. Early 350s are too. In 1977, Oldsmobile made all the SBO engines with windowed mains and they are weaker than the old blocks. The diesel 350 DX is the best Oldsmobile block among the small block versions. I wouldn't want to push a windowed block past 500 hp or so. But people like Dick Miller have gotten NA 403s past 600 hp. Wouldn't do it long tho. Probably 8th mile be best. They make girdles and main caps for them that add much strength. Head studs a good idea under heavy use too.
What cam did you run to go 7:50s in the 1/8th? Great videos. Thanks.
It was a Lunati Streetmaster.
245/245 @.050, 295/295 advertised, 569/569 lift, 108 lobe separation. Believe it was designed in the 1980s.
Also used studs, guideplates & adjustable roller rockers. Pretty much mandatory with a Olds engine with a big cam. Stock valvetrain limited to .500 lift or so.
@@thereluctantgearhead4544 thanks for the info. She ran real good for sure!!
You said at the end was getting hard to find that starting to be everything in our world bro it all got scrapped and turned into a Honda 😂and quality control doesn't exist anymore
That's no shit.
KB 405 .024 Pistons are still available. For my 1979 "Bandit" Y84 Trans Am, 2.73 rear End, AT, ..."One of these days", I would like to "Soup Up" (I'm Old School) it's 403. I want to maintain, at least in appearance, ALL SMOG equipment, AC, etc. I'm thinking KB405 .024 pistons, , MILD Cam (power from idle up or 1000 RPM up) Mild port and polish on the STOCK heads, Recurve the stock HEI distributer, re-jet the stock Rochester Quadrajet 4V carb. Maybe replace the stock exhaust "Y pipe" with a true, two into one, Y Pipe, flowing to the single, Aftermarket High flow cat. This for weekend street use. Comments please.
The old W-30 cams work pretty good for a mild driver. Headers and dual exhaust definitely help. A old stock 330 or 350 intake non EGR from the late 60s would help. Q-jet from early 70s 455 would work alittle better too.
Opening up the shaker scoop helps too. A 3.42 gear would feel like ya added 100hp compared to a 2.73.
The 403's were made by GM to replace the Oldsmobile big blocks in the smog era.
Yep, and a shitty replacement at that. But the late 70s was a pretty grim time for factory muscle. But they do have potential to be a good hipo street engine.
Pulled this one out of a wrecked 77 Trans Am decades ago. Built it up and gave it hell for years, I was surprised the bottom end never came apart.
How about a billet oil pan with built in crank brace ? That should strengthen it up.
There are some nice bottom end girdles available, but under 500hp or so it's not really nescesary. I was nervous about it when I first built the thing, but after driving it daily for 2yrs and running it at the track on a few occasions giving it serious hell, the bottom end never came apart. I wouldn't want to go any further with it without a girdle & o-rings tho. 6000 grand and under its pretty safe. Definitely not the best choice Oldsmobile engine for a all out effort. But they do make good street machine engines.
Looks fragile as hell for sure. I figured it would come apart when I took it to the track. But surprisingly it held together. Even played with a small shot of nitrous and ended up breaking a piston ring land doing nitrous burnouts on back roads for distance. That's when it got taken apart the last time. 30+yrs ago.
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