BBC heads question
06-07-2007, 06:45 PM
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Car: `84 Trans Am, `78 Monte Carlo
Engine: 350 TPI, 454
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BBC heads question
Which castings are better for 400-500hp 454 cid big block- 781 or 063 heads. i know that 781´s are open 114cc and 063´s are closed chamber 101cc heads.
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thanks
06-07-2007, 07:32 PM
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Car: 1986 Iroc
Engine: 454 Demon 850DP
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Re: BBC heads question
The 781's and the 049's seem to be a popular choice for the hp you are looking for.
06-07-2007, 07:34 PM
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Re: BBC heads question
The 781 has better flow between those 2. It will also work better on pump gas because of the chamber shape.
With 2.19" and 1.88" valves, and a normal bowl port, they'll feed about any street 454 well.
With 2.19" and 1.88" valves, and a normal bowl port, they'll feed about any street 454 well.
06-07-2007, 08:06 PM
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Car: 87 IROC L98
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Re: BBC heads question
The open chamber heads for a BBC are always better. It allows for bigger valves and they won't be shrouded. You adjust the compression ratio with a dome piston. Unlike the SBC, a BBC has a different combustion chamber shape and valve design so a dome piston doesn't hurt it.
I was running 781 castings before I upgraded. Bigger valves, upgraded valve train, port work and they work fine. When I punched a hole through one when I dropped a valve, I picked up a set of Merlin heads instead of reworking another 781 casting. I now have a small set of Canfield aluminum heads. They're only 310cc intakes. My engine could benefit with a set of 345cc heads.
I was running 781 castings before I upgraded. Bigger valves, upgraded valve train, port work and they work fine. When I punched a hole through one when I dropped a valve, I picked up a set of Merlin heads instead of reworking another 781 casting. I now have a small set of Canfield aluminum heads. They're only 310cc intakes. My engine could benefit with a set of 345cc heads.
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