The way to even the playing field is to supercharge the lil 396.
if your 396 already has flat top pistons the cr is going to be low.
Supercharger friendly low.
For a maturely asphyxiated street/strip 396 that runs on pump gas you want the cr to be between 9.5 to 10.5. Requires a piston with a dome. The dome volume required will depend on the actual combustion chamber volume of your heads.
Its all in the details.
Are you sure your 396 pistons are flat top? What is the piston part number?
Last edited by F-BIRD'88; 01-11-2011 at 06:41 AM.