[bobcowan]

Previous versions of twisted wedge cylinder heads required specific pistons to fit the non-stock valve angles. Be sure and check on the new versions.

53cc combustion chambers are kinda small, depending on the type of pistons you plan to use. Be sure and calculate static and dynamic compression.

Jasper is a pretty good rebuilder for stock replacement engines. Not so much for high performance stuff. Be sure and check deck height on ALL cylinders.