Rotors. This is far better than gtr r32 which just uses 295mm x 32mm rotors with the same pad size as z32, just the the caliper is cast different to extend over the rotor. I think the rear rotors on the v spec r33 or r34 are 22mm vs 18mm like z32 and non v spec gtr
Z33 is 12.75in by the way. But keep in mind 900$ is close to buying a brand new z34 frontbset up.