[Jac Mac]

Originally Posted by Fred W B

Hi Jac

I also expect I will have to reduce the compression ratio, by using the thicker composite head gaskets

Fred W B

No, keep the minimum possible squish distance ( piston to head distance @ TDC ) & lower compression by enlarging either piston dish volume or head chamber volume or if necessary a combo of both. Using thicker than necessary head gaskets increases the risk of detonation even though the comp ratio is lower. Since motor is not assembled yet I would machine piston dish-- dont touch the squish band--- & rebalance if reqd.

Oh, and while the pistons are out cut pressure relief & anti det grooves on the two top ring lands.