Correct pistons for rpm heads 360?

BTW, if you have the 63 cc heads, and if you have access to someone who will do reasonable cost milling, then you could take the KB190's and mill flat the small dome area above the eyebrows and then mill flat a small bit of the dome on the opposite edge (to accomodate the 63 cc chamber shape opposite the valve side). A rough estimate is that this will remove about 2.5-3 cc's of dome volume. With a .028" head gasket, the quench gap would be around .040", and SCR would be around 11.2. I would be sure to check the dome to chamber clearance all around if you go this route, as well as dome thickness (which I suspect will be OK).