rods are the same across the LA board, if your going to rebalance it. 4bbl spec Piston selection is like 3: NOS, Egge and JE (?) makes some really nice forged ones but any of the big piston makers (Probe, Ross, etc) could make you a set in any flavor. you can get KB high compresion 318 pistons and be car lengths ahead but i never see a 318 build with those.
