For $3200 you get all the parts I listed. The motor is in a clip and running. I'm not sure if you would want to ship the entire clip though as it would be more expensive than just the drivetrain. I can pull the drivetrain and harness out for easier shipping, but I'm willing to send it however you want. I do not have a driveshaft. The Skyline drive shaft would be useless in a Z anyway. The RB20 tranny uses the same yoke as the S30-S130 Z car. As a matter of fact, the RB20 tranny looks almost identical to the Z car one. At the worst you would just need to have yours shortened and balanced and it will slip right in. When I had my driveshaft done it set me back $140, and that was with all new U-joints as well. Your '83 ZX did not come with a factory LSD. The earliest factory supplied units are in the late '87 300zx turbo, from April of '87 and later to be exact. As for the clearance, with a ZX you have a fair amount more room to play with. Since it is a bigger car, you probably have more room up and down too. I can't say positively, but the plenum issue may not apply to your car. Regardless, there are ways to solve that. Let me know.
Brian