[Jeff Lee]

Irregardless of any of the other pistons being lighter than the TRW's, the newer quality brand pistons have more accurately cut ring grooves. Not that many have not gone fast with TRW's over the decades (but then again, all that was available was TRW for decades if you wanted a good forged piston that was affordable). It's all about ring seal and it's worth power.
If you keep the TRW's, just check the vertical and radial clearances with the rings you use. There are shims available to correct problems. Rebco offers plenty of options if you want.