I agree with B1MAXX seeing that you haven't finalized your piston order yet. .025" is very close tolerance between two opposing high speed cycling components (piston rock, rod and valve stretch,lateral valve movement,etc). I think now is the time to fix that clearance rather than later when all parts have been designed and built. Had recently FOUND a radial valve to cylinder clearance issue after all the parts were built. Would have been very costly to change. Do it now, you will sleep better. Bill