S10/blazer/Iroc rear end???


New Member
Sep 20, 2007
WIll any those show above fit a GN?? a disc brake 10 bolt??? if so how?? what years to look for the swap?? If not from which cars can i find a 8.5 posi diff??
the 442, grand prix 2+2 and any 84-87 turbo regal. the monte carlo and ss has the 7.5 in it.

if they have aluminum drums than its a open diff if they are iron drums than its a posi if the diff is still original and the drums are still from the factory and not replaced.

the blazer is a leaf spring differential. and is a 7.5 diff
Even the GNX had drum brakes in back, so there is no straight bolt in Rear Disk swap.
i don't think any 7.5 rear axle had rear discs until the 93 redesign of the F body- and brakes from those aren't a direct swap to a GN, since they finally got smart and went to the good old 4 bolt axle flange pattern across the GM rwd line.
the F bodies got rear disc brakes in the 80's- but in order to get that, the car had to have the borg Warner 9 bolt rear end with it's own screwy axle flange pattern.
there is no "easy" rear disc setup, but the axle flange on a G body can be modified to the 4 bolt axle flange and you can bolt on any GM passenger car rear disc setup you want- except for Corvette stuff and the 80's F body setup i already mentioned.
DAMN IT!!!!! oh well, hmm the adapter plate you mean, i found one on ebay, i think after that mod you can use a disc swap right. So which is better DISC or drum??? I just wanted to upgrade my front discs, but if i plan on going 140 will the drums take it or no??
drums are fine for stopping once or twice, but they start to fade fast and can be more touchy as far as lockup is concerned.
as for disc brake donor cars- the best junkyard bet would be the 94-96 Caprice. get the "cradle" bracket, caliper, hoses, and e brake cables from the donor car. don't bother with the rotors, becasue they are drilled for a bigger wheel bolt pattern and have a bigger center hole.
drill your axle flange for the 4 bolt pattern, and put it all together using 2000-ish S10 Extreme rear brake rotors.