What needs to be done to put a 9 bolt rear in a 82z.

 

Here's the instructions, in 2 easy steps:

1. Unbolt the 10-bolt.
2. Bolt in the 9-bolt.

If it has disc brakes, you'll need to get a 82-83 master cyl & proportioning valve for 82-83, since the fittings are SAE in those years where they're metric in later years. Same at the rear end; you'll have to cut lines somewhere and adapt them to the SAE size on teh car, because all of the 9-bolts will have metric lines.