Stock 400 2 bbl compression ratio

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Low! The one I pulled apart for my car the pistons were at least .080" if not .120" down the bore at TDC.
 
They were (theoretically) 8.2 to 1. That would be a perfect one where every tolerence was on the best side of perfect.
 
A 2bbl on a 400? OK, never seen that. On a 383, yea.

I speced mine out and it was 7.7-1 Yak piss could power that ratio.
 
I used the Kieth Black 240's and had the block zero decked. They have a -8cc dome from the valve pockets and with a factory open chamber head give you about 9.5 to 1 compression. These pistons require a larger than normal top ring gap so read the instructions if you use them. They are also much lighter than stock pistons. I also went with the 440source h beam rods and had the bottom end ballanced. A forged 383 crank is a good idea. It is a bolt in swap and can be had cheap. Just remember they are internally ballanced and the 400 cranks are not.
 
mischiefdart said:
I used the Kieth Black 240's and had the block zero decked. They have a -8cc dome from the valve pockets and with a factory open chamber head give you about 9.5 to 1 compression. These pistons require a larger than normal top ring gap so read the instructions if you use them. They are also much lighter than stock pistons. I also went with the 440source h beam rods and had the bottom end ballanced. A forged 383 crank is a good idea. It is a bolt in swap and can be had cheap. Just remember they are internally ballanced and the 400 cranks are not.
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Thanks everyone for your input. Mischiefdart, what formula did you use to get the 9.5 to 1 compression? I plugged in the specs on Keith Blacks website and it said 8.9 to 1 with 90 cc heads. 9.5 is what I want.
 
90 cc is alot of cc's.

Is milling that down a OK move to do for you?
 
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