21 Stud Piston Fit

[frnkeore]

I just received my Simi Finished pistons, for my late '36 engine. It will be .080 over or 3.142 basic bore.

These pistons measure 3.149 and are suppose to be finished by cam grinding the skirts.

What I would like to do, is turn them round, instead. What would be the desired clearance for a round piston vs a cam ground clearance?

I have the specs for ring land and ring depth so, that's not a issue.