Hey Fortynine5,
I just finished up putting one in my truck. It was out of an 88 IROC-Z...3.08 with posi/discs.
62" wide...backspacing of 4" on 8" rear rims w/255/70/15's. Swaybar bolts right up to existing holes in frame. No tire clearance problems whatsoever. You can see my application in my album.
The major limiting factor is the lack of R&P ratios....in this 9 bolt Australian-built Borg Warner. The 3.42 is the only other option.
I also looked at some drum diffs from second and third generation and they would have made a nice conversion. I went with the 9 bolt because of low mileage, posi and discs. Of course, 10 and 12 bolts are more popular....but I couldn't ever figure why a guy would go to all the trouble of changing out a 50 year old diff for a high mileage 30 year old diff. If you check out the Camaro diffs you will find that they are commonly used with 350-400 hp apps.
Hope this helps you with your selection.
