The rear end will work fine with almost all Zs that had an R200 stock. The only differences between the years is the input flange which must match your driveshaft. Usually you can simply yank the one off your old diff and put it on the new one. The transmission will not bolt up however. The 300zx front hubs will fit however and there is a mod to use the 300zx front brakes on the 1st gen Z. Some people adapt the 300zx fuel injection to earlier cars because it is free flowing and very accurate. Of course you would need an FI manifold from a 280z/280zx and a N42 or later head to use fuel injection.