which kbs???

ok but if i get kb107s and i dont have a 72 cc head and its less or if i get a thinner gasket that raises the compression

Yes.

dgc333 KB107 flat tops with typical unmachined block (0.012 to 0.018 in the hole),
Typical? Reallly. Not in my corner of the world. 2 engines out of car into machine shop with boring only and presto, zero deck. But your right about these things having the potential of sitting in the hole easy. Factory blocks have a small variable everywhere.