Always good habit to measure spring installed height. Cheap tool and easy to measure. You’d be surprised the difference in spring pocket depths. Just ensures you’re getting that seat & open pressures the spring is designed for.
The convertor should help alot also lower tire pressure 22lbs and try just the 1.6 rockers on the exhaust helps top end HP chevy have deficient flow on the exhaust side look at z6 vet cam for example 210intake duration 222 to 228 exhaust Crane always ground cams with more exhaust duration and old to new most chevys ran better with 1.6 and Newer with 1.8 ratio rockers on exhaust side.
This is a fun channel to watch as you build on your Firebird, reminds me of when I was doing the same in my youth. I have a question for ya though, could you remind us what gearing you are running in the back? Thanks, and keep up the excellent videos. 👍
Great video, thanks for all your work to do this. What's the rest of the combo? What cam, compression ratio, engine, heads, transmission and rear gear? Thanks.
@@Krikkebobbyracingchannel Ok, it's the compression ratio that's holding you back. There is a company from Texas that sells factory regrind roller cams on the Bay of e that are very affordable. Something in the around 210°/220° duration at .050" area with around .500" lift or higher would help your low end torque a lot. Those duration degrees or lower to as low as 200°/210° duration at .050" as close to .500" as you can get. Then do the 1.5/1.6 rocker test with that cam. You want low end torque when you're running a 700R4 to help recover from the one two RPM shift drop. With a low compression 305 even the 4.10 gears won't make up for the lack of torque that engine has with that cam, the RPM drop from the one two shift takes you down to low in the power band of that cam. I ran a factory sbc 305 Vortec with the factory roller cam and 1.6 roller rockers in my '64 Skylark with a 700R4 with a 3.73 rear gear. It weighed in at 3,400 lbs, 3,600 with me in it. The intake is an Edelbrock RPM Airgap and just a crappy Edelbrock 600 CFM carburetor. The car ran 14.0s in the QM. If you can afford it Comp makes a sweet XFI roller cam that I run in my '65 Impala with a sbc 383 backed by a 700R4 with 3.07 rear gears. It has the Weiand style RPM Airgap dual plane intake with a Holley 850 dp setup for fuel economy. Anyway the cam is 202°/212° duration at .050" with .550"/.546" in/ex lift using the called for 1.6:1 rockers with a 113° LSA. You don't have to have fuel injection to run that cam, works great with a carb. The Impala weighs 4,400 lbs and does 13.0s in the QM. Here's the kicker, I get over 20 mpg city and 26 mpg highway with that car driving with a light foot. If it had the right valve springs I believe it would be in the high 12s. The 383 has 9.6:1 compression with cheap Patriot Performance aluminum 195 cylinder heads. This engine and rear gear in the Skylark being 1,000 lbs lighter with the right valve springs would be a whole second faster in the high 11s. The above cam might help get you in the high 13s? Your car is lighter than the Skylark and the above cam is way better than the factory sbc Vortec cam. The unknown factor is that 8:1 compression. I think the factory sbc Vortec engines were around 9.5:1 from the factory? So I can't say for sure what you'll run but can say for sure it'll be better the cam you're running. With low compression you want to replace duration at .050" with lift. You really can't do that with a flat tappet cam though. Factory unported heads usually max out just over .500" lift so going a bit past that will keep you in the max flow longer helping fill the cylinder better without losing low end torque from to much duration. But your heads will need screw in studs for lifts higher than .500" and guide plates. Changing pistons to flat tops would help a lot for more needed compression. Can't wait to see what you do next.😎👍
@@itseithergonnaworkoritaint7852 3800 converter and NX kit. This summer while building something similar to what you are talking about. 305 vortex bored 30 over with flat top pistons and 500 lift cam and a single plane. Like to be in 12s on motor with a vortec combo.
@@Krikkebobbyracingchannel Being a Vortec block it's setup for a factory roller, one of those Texas regrinds would be the ticket. If you're going to take the factory heads in for a valve job and have the factory seal bosses machined down for higher than .465" lifts, you might be better off buying a new set of Vortec heads from the Bay of e. GM is having EQ repop their 305 and 350 Vortec heads that already have the seal bosses machined down and setup for screw in studs so you don't have to run self centering rocker arms. They're supposed to be thicker where the factory ones are prone to cracking too. You can sell the factory Vortec heads to recover some funds for the new ones. Not sure if they flow the same but Hatch's Recreational Engineering bought a set of the 305 versions of those heads for his sbc 307 and he went from 15.9 in the QM to 13.9!😳 He's still learning how to drive it to, with some tuning and driving technique he should be able to at least get it down to 13.5s or better? He did a heads, intake, carb, cam and lifters and 1.6 roller rockers. Basically a top end swap for the little 307. So by how his little 307 improved they should flow pretty close to the factory originals or better? He's running a genuine imitation RPM Airgap dual plane intake and a Holley 600 double pumper. If you don't have a forged crank and not running solid lifters flat or roller with the forged crank you're better off with a genuine imitation RPM Airgap dual plane intake. Cast cranks are only good for 6,500 RPM and so are hydraulic lifters. A single plane intake doesn't start making more power than an RPM Airgap until over 6,000 RPM. Below that the RPM Airgap makes more power, torque and HP.😎👍
@@Krikkebobbyracingchannel Oh and you shouldn't need nitrous to run 12s with a 350 Vortec if you choose the right parts that work well with the 700R4. My '65 Impala has a 3,000 lockup stall converter, works great with that little big cam in it. If you get the above mentioned heads bare, you can order valves that are .100" longer than stock so you can get the cheap LS springs instead of trying to get the more expensive sbc springs that will work for your cam. Sbc heads have a 1.7" installed height while the LS stuff has a 1.8" installed height. Valves .100" longer is just what the doctor ordered to use LS springs.😎👍
Well done. Thanks for the comparison.
Such a fun channel without any fluff or BS.
Thanks.
Nice work. Only way to know what works best is to try different things.
Always good habit to measure spring installed height. Cheap tool and easy to measure. You’d be surprised the difference in spring pocket depths. Just ensures you’re getting that seat & open pressures the spring is designed for.
It might also be nice to put lambda/afr gauge on it to fine tune the carb and timing.
@@joshmaust4901 car has a aem air/fuel gauge definitely has made carb tuning a lot easier.
You should try a set of drag radials
The convertor should help alot also lower tire pressure 22lbs and try just the 1.6 rockers on the exhaust helps top end HP chevy have deficient flow on the exhaust side look at z6 vet cam for example 210intake duration 222 to 228 exhaust Crane always ground cams with more exhaust duration and old to new most chevys ran better with 1.6 and Newer with 1.8 ratio rockers on exhaust side.
Nice
This is a fun channel to watch as you build on your Firebird, reminds me of when I was doing the same in my youth. I have a question for ya though, could you remind us what gearing you are running in the back? Thanks, and keep up the excellent videos. 👍
4:10 gears 700r4 transmission
I thought we put the 1.6 on the exhaust.
People wonder why there's so many cam failures
Great video, thanks for all your work to do this. What's the rest of the combo? What cam, compression ratio, engine, heads, transmission and rear gear? Thanks.
305 40 over 8:1 compression,tpi 081 heads, comp 280h cam, 700r4/2800stall and 4:10 gears
@@Krikkebobbyracingchannel
Ok, it's the compression ratio that's holding you back. There is a company from Texas that sells factory regrind roller cams on the Bay of e that are very affordable. Something in the around 210°/220° duration at .050" area with around .500" lift or higher would help your low end torque a lot. Those duration degrees or lower to as low as 200°/210° duration at .050" as close to .500" as you can get. Then do the 1.5/1.6 rocker test with that cam.
You want low end torque when you're running a 700R4 to help recover from the one two RPM shift drop. With a low compression 305 even the 4.10 gears won't make up for the lack of torque that engine has with that cam, the RPM drop from the one two shift takes you down to low in the power band of that cam.
I ran a factory sbc 305 Vortec with the factory roller cam and 1.6 roller rockers in my '64 Skylark with a 700R4 with a 3.73 rear gear. It weighed in at 3,400 lbs, 3,600 with me in it. The intake is an Edelbrock RPM Airgap and just a crappy Edelbrock 600 CFM carburetor. The car ran 14.0s in the QM.
If you can afford it Comp makes a sweet XFI roller cam that I run in my '65 Impala with a sbc 383 backed by a 700R4 with 3.07 rear gears. It has the Weiand style RPM Airgap dual plane intake with a Holley 850 dp setup for fuel economy. Anyway the cam is 202°/212° duration at .050" with .550"/.546" in/ex lift using the called for 1.6:1 rockers with a 113° LSA. You don't have to have fuel injection to run that cam, works great with a carb.
The Impala weighs 4,400 lbs and does 13.0s in the QM. Here's the kicker, I get over 20 mpg city and 26 mpg highway with that car driving with a light foot. If it had the right valve springs I believe it would be in the high 12s. The 383 has 9.6:1 compression with cheap Patriot Performance aluminum 195 cylinder heads. This engine and rear gear in the Skylark being 1,000 lbs lighter with the right valve springs would be a whole second faster in the high 11s.
The above cam might help get you in the high 13s? Your car is lighter than the Skylark and the above cam is way better than the factory sbc Vortec cam. The unknown factor is that 8:1 compression. I think the factory sbc Vortec engines were around 9.5:1 from the factory? So I can't say for sure what you'll run but can say for sure it'll be better the cam you're running.
With low compression you want to replace duration at .050" with lift. You really can't do that with a flat tappet cam though. Factory unported heads usually max out just over .500" lift so going a bit past that will keep you in the max flow longer helping fill the cylinder better without losing low end torque from to much duration. But your heads will need screw in studs for lifts higher than .500" and guide plates.
Changing pistons to flat tops would help a lot for more needed compression. Can't wait to see what you do next.😎👍
@@itseithergonnaworkoritaint7852 3800 converter and NX kit. This summer while building something similar to what you are talking about. 305 vortex bored 30 over with flat top pistons and 500 lift cam and a single plane. Like to be in 12s on motor with a vortec combo.
@@Krikkebobbyracingchannel
Being a Vortec block it's setup for a factory roller, one of those Texas regrinds would be the ticket.
If you're going to take the factory heads in for a valve job and have the factory seal bosses machined down for higher than .465" lifts, you might be better off buying a new set of Vortec heads from the Bay of e. GM is having EQ repop their 305 and 350 Vortec heads that already have the seal bosses machined down and setup for screw in studs so you don't have to run self centering rocker arms. They're supposed to be thicker where the factory ones are prone to cracking too.
You can sell the factory Vortec heads to recover some funds for the new ones.
Not sure if they flow the same but Hatch's Recreational Engineering bought a set of the 305 versions of those heads for his sbc 307 and he went from 15.9 in the QM to 13.9!😳 He's still learning how to drive it to, with some tuning and driving technique he should be able to at least get it down to 13.5s or better? He did a heads, intake, carb, cam and lifters and 1.6 roller rockers. Basically a top end swap for the little 307.
So by how his little 307 improved they should flow pretty close to the factory originals or better? He's running a genuine imitation RPM Airgap dual plane intake and a Holley 600 double pumper.
If you don't have a forged crank and not running solid lifters flat or roller with the forged crank you're better off with a genuine imitation RPM Airgap dual plane intake. Cast cranks are only good for 6,500 RPM and so are hydraulic lifters. A single plane intake doesn't start making more power than an RPM Airgap until over 6,000 RPM. Below that the RPM Airgap makes more power, torque and HP.😎👍
@@Krikkebobbyracingchannel
Oh and you shouldn't need nitrous to run 12s with a 350 Vortec if you choose the right parts that work well with the 700R4. My '65 Impala has a 3,000 lockup stall converter, works great with that little big cam in it.
If you get the above mentioned heads bare, you can order valves that are .100" longer than stock so you can get the cheap LS springs instead of trying to get the more expensive sbc springs that will work for your cam. Sbc heads have a 1.7" installed height while the LS stuff has a 1.8" installed height. Valves .100" longer is just what the doctor ordered to use LS springs.😎👍