All Z32s come with LSD diffs standard so why go backwards .The late 87-89 Z31 Turbo came with both clutch type and Viscus type LSD rears in 370 ratio only but they are long nose (The pinion shaft is longer so it will NOT bolt directly into the Z32 ),The Z32 N/A is a 408 gear ratio and the TT is a 336.But is the larger 230 MM ring gear Stick with what you have and stay away from the Z31 parts they are hard to find ,expensive and will not work in the Z32 without MAJOR fabrication