I am starting to build a 396 with a forged bottom end, flat top -5cc pistons, AFR 220cc Compitition heads, and a solid 260/260 .660/.660 cam and a HEI style pro-billet distributor. I was wondering what kind of compression should I set my DCR to allow me to use 93 octane pump gas safely and still run 36 degrees of ignition advance?

 

A search will yield great results. It's been beat to death here.


With that being said 9.0 is about the max you wanna go and that is with good cooling, tight quench, and a good tune.

 

BTW, If you've already purchased the parts listed, your DCR is already "set". Cylinder head combustion chamber volume, piston dish volume, and valve timing all affect the dynamic compression ratio.

 

If ya have a .035 quinch ya may not need 36* of timing.With that cam ya are needing a 12-12.5 static to get to a 9.0 DCR(guess not knowing the cam spects)