The bolt pattern is 5 on 43/4" just like the F bodys(firebird camaro) and 2wd S10's, and most other RWD GM's. The offset is different though, more like a front wheel drive. I'm not sure but I believe its around 4". Hope this helps.
1989 S10 4x4 355
1989 SBlazer 4x4 4.3