Hey yall, im new here and need some advice. I got a 79 camaro. It was a v-6 car, but I put a 454 in it and a Th-400 trans. Not sure what to do about the rear end yet. I just pulled it out, sand blasted and painted it so far. I know its got an 8.5" 10 bolt open rear with smaller diameter 28 spline axles and 2.73 gears. My neighbor has a HUGE junk yard and said i can have whatever i need. I was wondering is there another vehicle i can pull a posi differential out of that would bolt into my axle housing?? I popped the cover off an 89 s-10 blazer that has posi 3.73's, it looks similar. Would the guts be interchangeable??? Any certain vehicles to look for parts out of?? He just got in a 95 LT1 camaro with a posi rear but i doubt anything would interchange on it.

Thanks,
Don

 

Not positive,but i dont think the one from the blazer would fit,i think they have like an 8.2 rearend.Best bet would be to find just about anything from the mid 70's through very early 80's that would have a posi,i'm pretty sure that's about the time frame that the 8.5 rearend was used.

 

those 89 s-10's and s-10 blazers had 7.5 rearends same as in the 3rd gen camaros so they'd be to small.

 

Personally, I would just keep an eye on Craigslist for a bolt in entire rear end. Rebuilding the insides is not as easy as you think. I have seen them as low as $250 up to $500 as an average. Sometimes somebody REALLY thinks they have something and wants $1200 for it. But I just found one on a car I purchased along with someone else, all I wanted was the front sway bar and the rear end, I'll put my rear end under it, and they get the car.

 

I'd second ATM! Try to find a good 10 bolt posi with the right gear range you want. Camaro or Firebird, but measure the spring perches and the overall length to ensure it's a match for your car. 70-81 Camaros and Firebirds are all the same width. The 8.5" rear goes clear back to 1970, but not sure if all of them from 70-81 were 8.5" or not. You'll need to check that when you pull the rear cover to inspect it.
I've got close to $1,000 into making my 10 bolt strong, and a factory 10 bolt posi wont be as strong, but it will be a lot cheaper.