I found that the 2nd and 3rd Generation Camaro diffs were all 62", wheel mounting surface to mounting surface, same as the stock AD. The Z cars also had posi/discs and commonly came in 3.08, 3.42 and occasionally a 3.73. I use the 3.42 from a 2.8L automatic Camaro behind my .72 T5 with a 28.5" tall tire, a 15X7" rim with 4" BS on front and a 15X8 w/4"BS on the rear. Runs 2K at 65-70 in 5th and will drop down to 50-55 without a downshift.
Aside from being cluttered up with a lot of extra brackets that are easily torched off and a 2-5/8 axle tube which is easily shimmed to use 3" u-bolts...they mate up with the S-10 SWB driveshaft and are readily available. Most can be had for between $100-150. which makes them fairly attractive for use with a 235 engine and a T5 transmission.
Just another option that I know fits and works great! I have some pixs in my webshots "shoebox" album of the install. Hope this helps.
Dave