Anyone here ever have their pistons machined?

Why go thru the trouble of milling the pistons down .040"? If thats what you want to do, just put a thicker head gasket in. I have run head gaskets up to .165" before, MLS Cometic. Hell of a lot cheaper and easier than pulling the whole engine down and milling pistons.

Anyhow, just so some of us dont have to read for 2hrs, give us your basic combo so we can help

What stroke
What pistons, p/n and specs
What is your piston to deck clearance? Under, even, or above? How much?
What heads, known chamber cc, no guessing here
What cam and where is it installed, what ICL, again no guessing
What exhaust
What intake
What size carb
What dist are you running, Known Curve or unknown?