Raising Compression Ratio w/ Head Gaskets
you will get the best results if you go back to early '60's heads; either the 55 cc oreven better, the 46-49 cc heads. hipo heads with flat tops were 10:1 motors with the 46-49 cc heads stock. all oem heads have the same porting potential, its just that you must remove more metal in the ports of the early heads.
S/ST 1818 S/P 1018 H/R 1564