racelife wrote:
the s-10 rears came in 7.5 and 7 5/8 if they would have put an 81/2 in the s10 alot of people would be running them. they would be stronger and would hold up to a v8 easier.
they did put 8-1/2's in the s-10's I had one. Factory 4.3L L35 with the 5 spd came std witht he 8-1/2" and that is why you do see some racing them. Bill Mach out of MI has procharged these bastards to 12 seconds in the 1/4....s-seriesforum.com has an ID guide on the rear axles.
but back on topic,
the 7-5/8 is far more common in the scrap yards. If you run the 7-5/8 or 7-1/2 I would keep it setup as an open diff instead of a posi or locker as they break pretty quickly with that much additional HP and no way to bleed it off (IE wheel spin).
For what your looking to do 87pupsbc, you might seriously look at the Vega rotor conversion ont he front, that would get you on a 5 lug setup and might be the most inexpensive, correct, way about it.
I'd be leary about redrilling the original hubs for a 5 lug conversion....you might want to check with guys that have done it before just to make sure its completly safe. I'd hate for you to crack the hub because it was redrilled.....just remember the more holes you put into the original hub casting, the more material your removing which changes the load bearing physical properties.