If this had the brakes this is kinda what i'm talking about.
http://www.ebay.com/itm/Nissan-Skyline-GTR-R32-Engine-Jdm-RB26DETT-Engine-GTR-ENGINE-R32-RB26-T-LSD-DIFF-/271077663648?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f1d7ce3a0&vxp=mtr
Pull the diff, axles, and use the TTT rear conversion. Then cut out the stock Z engine bay frame rails and wide in some new rails a little wider so the sub frame bolts in. I know it would be harder then it sounds but that is about the easiest way i can think off. I was looking at some of the measurements between the z and gtr. The strut mounts are actually pretty close.