Ran a search but didn't get any hits on clearance for new pistons. They are cast .030 overbore, low compression. 330 Engine, manual transmission. I am going to the machine shop tomorrow with block and everything else. I said to hone for .002 to .004 clearance. Is this too much, not enough? I know forged pistons need more clearance, but what about cast? Any info will be helpful.

 

It depends on the piston as well as the amount of cam or barrel shape in the skirts. Typically .0015-.002 is common.

 

I agree with mark, .002 +/- for cast pistons. Also keeps ring gaps nice.