I would like to put rear positraction on my car(85 Camaro) but idk what car to take it from please help

 

Wonder why no one has responded. I would think you could find a posi unit in a similar year z. But what really matter is what rear end do you have. Sorry but I don't know what was available in 3 gens.

I think you have a 10 bolt 8.5. Just count the bolt on the dif cover. Then 8.5 is the length of the pinon. I can tell by looking but.. Not sure how to tell you the difference.
You can get a posi out of any other 10 bolt 8.5. Like one from a second gen.

But it is a lot of work and expensive to add a posi.
This is a better way to go: Powertrax Lock-Right Lockers - SummitRacing.com

You can install one in about 20 minutes. They are better, stronger and cheaper then a factory posi.

Just put in your make and model and summit will display the correct one.

 

Heres why no one is answering........

Be more specific. What do you mean by 'what car to take it from'?

Are you looking to swap an entire rear end? If thats the case, you will need to hunt down a 3rd gen with a posi.

Are you looking to swap the internals? Good luck on that. You need several very specialized tools and gear. If you cob job the install and guess on your setting, you WILL frag your rear end.

Why do you want a posi?

 

Only cars are 3rd gen (9-bolt 7.75 & 10-bolt 7.5 & 7.625) 4th gen (10-bolt 7.625) Camaro/Firedird ONLY...nothing else will work. You need to look for cars with RPO G80 (LIMITED SLIP REAR) and NOT positraction.

Or buy aftermaket LSD carrier which will be expensive for labor and parts. Estimated costs for both options around $300 to $700. A lot of money to do 2 wheel burnouts.

 

Positraction was CHEVYS term (nick name if you will) for limited slip just to educate on that term. Now everyone uses it as short 'posi'

Mopar has sure grip , AMC has twin grip, Ford traction lock, Oldsmobile Anti spin, Pontiac safty track...and so on.

IF you are ;looking for a Limited slip differential for your 3rd gen CAmaro you need to know it is a 26 spline axle unit for the 7.5 or 7.6 1982-1989
The 9 bolt Austrianian rear was a bolt in axle 28 spline unit... IROCs with DIsc brakes were usually the optional standard for that rear.

SO lets hope you have the most common of the 2 rears 10 bolt 7.5 rear.

List of some vehicles you can get the LIMITED SLIP / POSI unit from
all with standard 7.5 10 bolt -
1975-1980 Monza Vega
1975-1980 Nova apollo skylark
1978-1988 G-body Monte carlo, Cutlass, Grand Prix, El Camino , Malibu, Regal (non GN turbo coupe)
1882-1989 s-10 (might not be as desireable as it will have a gov lock limited slip locker)
1982-1989 Camaro, Fire bird, Trans Am
1978-1988 v6 Impala and other small engine B- body platform cars beieve it or not some had the little 7.5 rear in it.

As far as a complete whole rear assembly bolt in drum to drum rear - 1982 -1989 camaro firebird trans am is it unique to that car.

There are different GM posi units
Gov locker posi small truck units
Auburn cone type posi car unit
both are found in 2 and 3 series carrier units meaning they hold different ratios

2 series ratios are 2.14 2.29 2.41 2.56 2.73 2.92 3.08
3 series ratios are 3.23 3.42 3.73 3.90 4.10 4.30 4.56


Hope this helps

PM me if you need more info or limited slip

Jim