Deciding on piston to wall clearance for L2322F TRW

These are for de-stroking a 340 to a 305, I will loose over a full point of compression in the process (hopefully won't be too high when all is said and done). That is why i am using the dome pistons on this motor. With a 68cc chamber and .038" gasket a stock 340 works out to 12.25/1 and a 305 works out to 11.21/1 (still too high). Milling off the 10.7 cc dome works out to 10.6/1 for a 340 and 9.71/1 for a 305.

I will first have to wait and see how the open chamber cylinder heads check out and go from there.