GTRs are all 4WD but are TOTALLY different to all other models.

Different bodyshell shape, different kit, different block, different head, different internals, different turbos, different transmission, different interior.
Almost no interchangeable parts what so ever. And when i say "different" i mean "better"...

GTSTs are all RWD barring the R32 GTST4s i mentioned.

GTS is non turbo, GTST is turbo RWD