Magnum slug weight vs...

Be careful comparing piston and pin weights ONLY! What allows the Icon and KB pistons to be used is the Piston/Pin/Ring weights...must include the ring weight to keep the bobweight the same as OEM. If you use a piston/pin combo that has lighter rings, the balance can be off by 15g or more making balancing necessary.
Would ether slug be a HyperU?