okay so ive searched and searched and i cannot find what i need anywhere! i have a 1971 240z and a piston was broke i need to know the size and where to buy them thanks to everyone who helped.

A machine shop can tell you the size, they will have the correct measuring tools, STD size should be 83 millimeter, but you can't tell if it have been bored once, not without measuring, always replace pistons in a set.

Chris

alright thanks for the help i will do that do you know what a set of six pistons will run me?

I've seen them for about $240 per set.