# Posi Unit for a non posi 10 bolt rear



## 69Tribute (Jul 22, 2019)

Hi All: Upgrading a non-posi 10 bolt in a '69 GTO Tribute with 3.08 gears to a posi with 3.73 gears. What is the best posi unit for the factory differential, Auburn, Eaton? Thanks!


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## Nicholas (Jan 16, 2017)

Not sure which is best. I never bought or used one, but I did have an interest in a posi unit at one time. I did a little research and if I recall properly, the biggest difference, maybe the only one, is that the Eaton unit is rebuild-able and the Auburn unit isn't. Geez, I hope I have that right. I don't think that was ever an issue for me if I decided to buy one. Considering the amount of miles I would put on it a year, I wasn't worried. I ended up buying a factory posi rear instead, Nicholas.


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## john23 (Mar 6, 2016)

check out Tru-Trac differentials. i installed one and have never looked back. they don't use springs, rather they use gears to provide the differential function.


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## bigD (Jul 21, 2016)

Yeah, you have a choice. Some like the clutch type. Some don't.

Since both are still sold, I have to assume that each type has at least one advantage over the other. 

If you still have the BOP 8.2 10-bolt, make sure you buy parts for a BOP & NOT a Chevy 8.2. 

Here are some BOP packages, mixed in with some Chevy 8.2 stuff. Can also be ordered from Summit, Jegs, Amazon, & most of the big drivetrain shops. 

https://www.ebay.com/sch/i.html?_fr...sc=0&_osacat=0&_odkw=bop+posi+with+3.73+gears


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## PontiacJim (Dec 29, 2012)

69Tribute said:


> Hi All: Upgrading a non-posi 10 bolt in a '69 GTO Tribute with 3.08 gears to a posi with 3.73 gears. What is the best posi unit for the factory differential, Auburn, Eaton? Thanks!



Read through this entire post. I explains the assorted types of limited slip/locker type carriers: https://www.randysworldwide.com/resource-center/limited-slip-differential-locker-spool-differences/


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## dcoydad (Sep 27, 2017)

I still have a XD posi out of a 69 Judge for sale. It has .390 gears with nodular case and forged axels. Call if interested. Steve 405 609-7077


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## John Schutt (Aug 27, 2018)

I'm no expert on this, but I have done some reading and have experience fixing things that can't be fixed, not rigged to get home, fixed so it will last like factory or better.
I read where the cone type is not rebuildable, my neighbor has a '71 Plymouth Duster that came from the factory with the cone type. it was not acting right, he took it out and sent it to Cleveland, OH where it was rebuilt. Looking at the pics i'd say they weld the cone area, draw the weld back to the original hardness, machine it back to factory specs.


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## GMCSIERRA35 (May 16, 2019)

I just did the exact same upgrade bop 10 bolt 8.2, had 3.36 gears went to 3.73, yukon grizzley limited slip. I have been very happy so far with it, other than breaking it in i havent been gentle on it. I did end up with bad wheel hop after the switch and went with lakewood no hop lift bars and that cured the problem.


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