Well, I kind of fell into getting these Speed Pro pistons.

Would it be beneficial to go with the KB 400?

I may save the 2315's for another build since they were basically given to me (not free but cheap)

I checked my CR with the 400's if I buy them, 9.8:1 with the 84cc head and .027 gasket AND since the piston is .012" shorter I am ASSuming now .022 in the hole...which would give a quench of .049"...not ideal probably but I wouldn't think it was too bad.

How about this option? Plus, the valve relief "problem" if it exists would be solved.