If you're looking for suspension, the rear can use 300zx (Z31 only) suspension, and the front will use 280zx (s130) suspension. it comes with an R-180 diff (might use U-Joints instead of CV's...but I haven't seen one in a long ass time). So if you want to switch out the diff...you pretty much have to get an R200 and new axles, possibly a custom mount. A lot of people opt for the sr, or ca18Det, over the ca18Et, or the VG30; for power and space saving options (respectively). Of course if you get an SR you'll have a HUGE aftermarket (just to keep in mind).