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Discussion Starter · #1 ·
Hi everyone. I have a set of 041x heads on my destroked 400sb I didn't build the motor so I don't know much about it other then it's a destroked 400 that's been bored .40 over. Makeing it a 385? It also has flat top pistons in it. My question is would I make more Torque with the flat tops or domed pistons with the heads that are on it?
 

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If it was destroked using the common 350 crank that is most commonly used, it is 379 cubes at .040" overbore.

You will make more torque with the domed piston simply because compression ratio will be higher. Definatly high enough race gas will be mandatory, 12.5 to1 compression or higher. Right now with the flat tops you are at 10.8-11.0 to 1 area.
 

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Discussion Starter · #3 ·
If it was destroked using the common 350 crank that is most commonly used, it is 379 cubes at .040" overbore.

You will make more torque with the domed piston simply because compression ratio will be higher. Definatly high enough race gas will be mandatory, 12.5 to1 compression or higher. Right now with the flat tops you are at 10.8-11.0 to 1 area.
So pump gas is totally out of the question? Or could I get away with an Octain booster?
 
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