Front suspension (Disassembly) is standard MacPherson strut design. Rear suspension (Disassembly) is standard semi-trailing arm design. Only the toe is adjustable on both front and rear.
Many 300ZXs have problems with excessive negative camber in the rear. This can be fixed in a variety of ways:
The ball joints in the front are replacable WITHOUT buying new arms and joints. Simply remove the arm and press(hammer) the old balljoint out(After removing the snap ring that holds it in!!!) A balljoint is much cheaper than an entire control arm and ball joint. You can even get greasable joints that will outlast the car.
Another usefull modification is to transplant the 88-89 style tension rods onto your 84-87. All that is needed is the 88-89 tension rods and 88-89 tension rod brackets.
makes front camber plates for 84-89 300ZXs.
Prothane polyurethane suspension bushing kits are available from MotorSport Auto, one kit has all the bushings for all years/models of Z31.