The blocks, and heads are the same. The TB is the same, the supercharger is the same. Everything on the motor itself is the same with a few execptions. The MAF sensor can vary year to year. The harmonic balancer from an H-body is superior to that from the W-body.
Accessories and coil brackets and mounts are different though.
This is comparing L67 series II to L67 Series II, L32 Series III motors are different in regards to internal rods (although compatible) lower intake, supercharger, and TB.