Just measure and check the gear ratio. That can tell you alot where it came from. My v6 s10 had 3.42, my zr2 had 3.73 and the four banger had 4.10. Also they made alot of differant axle splines. most had 28. but there are a few 26 out there. And if you want to put and power down. forget it with that. The best rear end came in the g80 build code. found on alot of 2wd extreme blazers. 8.5 30 spline posi with disk brakes. That the rear end im looking for.