Vin "m" vs vin "k" piston questions

[91dirtydiesel]

Anyone know all the differences of the rods and pistons? I know wrist pins are better but are the pistons hardened? Coated? Different material? Shaving about .060 ish off of them and would like to know what I'm dealing with...or are they the same as the N/A pistons?

Thanks for any help