How much will 70cc heads raise my compression? Also how much lift?

Marcohotrod said
a flat top with no valve reliefs is 0 dome volume/height. if U use the shim gaskets spray both sides with Permatex copper coat

This - spray both sides, let get tacky, and lay them down.. worked great..

Link to the CR calculator -

https://www.rbracing-rsr.com/compstaticcalc.html