[Mike Taylor 3601]

Depends how much pistons rock, RPM,weight,.Have run down as tight .026 with .004 cly. clearance@ 6500 RPM. Check with cometic they have several thickness/bore combo. SCE makes copper that doesn't
use o ringed block. Cheapest way is use fel pro 7733 pt( thicker than min. thickness) Then reduce deck clearance
to adjust for thicker head gasket. You are allowed to reduce deck clearance for thicker than min. head gaskets.
Mike Taylor 3601