Combustion Chamber Size with Blower


Founding Member
Jan 24, 2002
Olathe, Ks
I am performing a 331 rebuild and will be purchasing new heads at the same time. I currently have GT40 Iron heads, but want to get new aluminum heads.

Considering I will be going with a 331 combustion chamber size should I go with for a proper Compression Ratio for a blower at 10psi?

I assume I should also get "blower" or dished pistons, is that correct?
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For 10PSI I would get the combustion/piston combo that would yield a 9.5-10.0:1 compression ratio, this will still allow you to have decent drive ability around town and get the power to come in a bit sooner than with a lower compression/higher boost combo.
Thanks for the info. I also forgot to mention that this is not a daily driver that will see most of its time at the track.

Do you have any idea which combo may work best, or how to figure compression ratio?