New engine build - 300hp tbi

[89GMCJOHN]

Straightened out your photo of your dyno chart 366 TQ at 2900 299 HP at 4900...nice flat torque curve

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[Gramps]

Gramps, which intake manifold/intake manifold gasket did you use? I have the same heads and I've mocked up a couple different manifolds with them. None of the manifolds look like they'll seal the recommended Fel Pro 1255 gasket.

I used the stock felpro tbi intake gaskets (MS93317) with the original stock gm intake manifold.

 

[Gramps]

Straightened out your photo of your dyno chart 366 TQ at 2900 299 HP at 4900...nice flat torque curve

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Thanks yeah it should pull really nice in the truck..... hoping to get it back together before the fall. Time running faster than I can though ha.

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[L31MaxExpress]

I used the stock felpro tbi intake gaskets (MS93317) with the original stock gm intake manifold.

You mentioned wanting to put a 454 TBI on this. I think the best bang for the buck would be a better intake manifold. I picked up 3 tenths of a second in the 1/8 mile and nearly 2 mph swapping out a Shaved/Moded 350 TBI and Edelbrock TBI manifold for a 454 sized 350 Marine TBI and Performer RPM on a stock long block 350 TBI with boltons. Only internal engine change at that time was 1.6:1 full roller rockers.

 

[Gramps]

The 454 tbi though was only because the 350 tbi is the bottle neck. Can’t quite get enough flow out of it. So it starts building vacuum again in the higher rpm range which hurts the total hp. But it’s not a high rpm built motor, and the throttle response will be quite snappy with the current setup.

 

[arrg]

I used the stock felpro tbi intake gaskets (MS93317) with the original stock gm intake manifold.

Thanks for the reply! That one overhangs the top of the port on the head on mine, but it does at least look like it will seal. Guess I could trim the gasket a little to make it fit.

 

[Supercharged111]

That's a big spread between torque peak and hp peak. Bigger than stock actually, plus it doesn't fall off after 5000.

 

[L31MaxExpress]

That's a big spread between torque peak and hp peak. Bigger than stock actually, plus it doesn't fall off after 5000.

Good breathing heads will do that.

The split on my Express van with the 205cc Aluminum heads and 215/224 @ .050 roller with 1.7 rockers is 2,200 rpm. Peak torque at 3,600 and peak HP at 5,800. I actually make more HP than TQ.

Where I made peak TQ at 2,900 rpm with the 395' cam and 1.7 rockers with 906s that had 2.02/1.60 valves the new setup is already up 20 ft/lbs. At 4,500 rpm I am already up 60 ft/lbs. Made a BIG difference when my trans downshifts to 3rd on long uphill pulls with the travel trailer behind me. Not to mention I can run a bit more timing than I could before on 93 octane. I am running the same advance curve I ran on E85 before.

I ran it from a dead stop through the 6,000 rpm 3-4 shift the other day. Took around 1/2 mile to accelerate the 6,500 lbs brick up to 115 mph from a stop.

 

[Gramps]

I don’t know that the intake would be a worth while upgrade. At least for this build. Most of what I’ve read is the edelbrock intake ends up hurting torque but does gain top end hp.