318 combo help

I have run that ratio with iron heads and anPurple 292/.509 Hyd. On 93 octane. I don't know if you can do less octane. Take your time tuning the carb and distributor in.

The move to closed chambered heads IF your Pistons will clear the closed chamber will go up a point close to about 11-1, give or take.

I'm running a 11-1 / 360 now. Flat tops and Edelbrock heads. The cam is a sizeable solid cam for the street.