i am sending my ls block off to get a bore + hone for my cp pistons. what ptw clearance should i shoot for? ls block 400-500whp. its going to be my daily driver during the summer. i see on the sheet that came with the pistons it says .0035. should i go for a little bigger, like .004 or .0045?

 

I went with .0045 on mine but .004 is good.

 

Unless they have changed, I was under the impression that if you buy an 81mm piston you should bore to 81mm exact. The tolerance is built into the piston.

 

That is true but I always send the pistons with the block to the machine shop regardless.