how much compression for pump gas

Interesting specs. That closing point would be "normal" on a much larger cam. So it will bleed a ton off at idle and low speed. You can try to lower that roof as much as you want. No way it will efver have any quench value. But that cam will tolerate a bit more static ratio without problems. I aim for dynamic of 8-8.1 max on iron heads and torque peaks below 3500. I'll go as high as 8.5:1 with alumimnum, decent quench, and higher peaks. You could mill the heads, but you'll need to mill the intake flanges too, adn probably either buy shorter pushrods, or rocker shaft shims to get the geometry right. You're spending either way.


edit: IMO, you're overcammed. you could use a thin gasket (.020) and get 10:1. But a better cam choice with the less static will feel and be faster in a street/strip car.