KDXRIDER.NET

So does everyone use an inside micrometer every time they do a top end? Could I just match the piston that's in it? If it's an A, get an A. If it's a C get a C?

I do not. You might take it to a machine shop to get them to do it. Just look in the manual to see how far down it is supposed to be. Once you get it checked and get the correct piston, you will be able to know a baseline for the future.