BBC Heads - Team Camaro Tech
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post #1 of 3 (permalink) Old Sep 8th, 18, 03:33 AM Thread Starter
Probationer
 
Join Date: Sep 2018
Posts: 1
BBC Heads

Hello all. I’m new to the forum and have a question about some heads for my 454. I have an 86 dually with a 445 casting block and 045 heads w a mild cam. Would 781s with oversized valves be an improvement for bottom end? The truck is a 4speed with 4:11 and I am only concerned with torque.
Randerson is offline  
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post #2 of 3 (permalink) Old Sep 8th, 18, 08:04 AM
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Dave
 
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Location: Tampa, Florida
Posts: 4,587
Re: BBC Heads

The difference in the two heads is found in the size of the valves and the combustion chamber (both have 230 cc intake ports as this was an early design head made from 1978 to '87).

You have a 122 cc combustion chamber instead of the 119 cc found in the '781 and the valves are much smaller and heavier than replacement Manley tuliped stainless steel valves that measure 2.30" intake and 1.88" exhaust. Larger valves would make it breathe better, but the cost to machine the head and replace guides would equal the cost of a new aluminum head to replace it.

Better plan to build torque would be to convert your 454 into a 496 by boring it and stroking it with an Eagle or Scat rotating assembly. That will yield a noticeable jump in bottom end torque. You can surface the heads to build more compression or just buy a rotating assembly with a slight dome on the piston to do the same thing.

Big Dave
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post #3 of 3 (permalink) Old Sep 8th, 18, 08:58 AM
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Beth
 
Join Date: Mar 2018
Location: Nashville TN
Posts: 481
Re: BBC Heads

Quote:
Originally Posted by Randerson View Post
Hello all. Im new to the forum and have a question about some heads for my 454. I have an 86 dually with a 445 casting block and 045 heads w a mild cam. Would 781s with oversized valves be an improvement for bottom end? The truck is a 4speed with 4:11 and I am only concerned with torque.
I would contact Vortecpro over at Team Chevelle. He reworks "peanut port" heads that make amazing low end power.

That's what you need - small cross-section but efficient ports to generate torque.

Vortecpro's name is Mark:

https://www.chevelles.com/forums/mem...vortecpro.html

It does seem to me you need an overdrive. 4:11's will be spinning that motor at high rpm all the time.

68 Camaro convertible, 6.0 LQ4 with LS3 heads, Vintage Air, 750 street demon carb, eddy perf rpm, GM hot cam, Hooker headers, 4L80e, 12 bolt, 3.55 gears
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