The only "stock" 82-92 rear that wasn't a 7.5" 10 bolt were the Dana 44s found in the 92 Firehawks (only 25 of 'em). GM never put anything else under the 3rd gens, so you won't find anything common (although GMPP did sell the bolt in Dana 44s for a while - I have one ready to go in my car

).
IMO, either drop the coin on a good aftermarket replacement (9 inch, 12 bolt, or Dana 60) or just buy a stock 10 bolt from another 3rd gen on the cheap to get you by until you can afford the proper aftermarket replacement.
You can always get an aftermarket posi / gears / axles / diff cover / etc, for the 7.5" but they are all only patches for a small, weak design.
- Justin