when it comes to heavier parts is that a lighter flywheel does not store energy as well as a stock one, which translates into more initial torque.... but once you're moving, the lighter components should more than make up for it. There are some engine// car builders that lighten all kinds of components, from camshafts to axles, with these gains aimed at reducing reciprocating weight. The purpose of going with aftermarket pistons and pins shouldn't be just to save weight, and you won't gain anything substantial from those few grams..but you will undoubtedly gain leaps and bounds in reliability and longevity by reducing weight on reciprocating internal components , plus aftermarket pistons will take more abuse and continued boost. Consider upgrading your rods while you're in there...
