unshrouding exhaust valves

The static C/R with fel pro 8553PT gaskets (.053) is 9.68 and the dynamic is 8.531. That's with the Magnum heads opened to 70cc's from 64cc's. With the heads left as is and a .039" gasket it's 10.687 static and 9.404 dynamic. A little too much for pump gas. That's the numbers I get from KBs web site.