Anyone know what this is?
 

I bought this because I was told it was an auburn 10 bolt 7.5 posi for 28 spline axles, but after running the #'s off of it I've been unable to match it to anything. The #'s i've found are # 71189 and a # that has been etched in by hand reads 8J97-59A. In the first pick there's a casting mark right below the bearing that looks like a P inside a D. The mark down and to the right from that one is a C or G. Thanks.

Attachment 240460

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Attachment 240462

Re: Anyone know what this is?
 

None of my Auburns ever had that blocky thing in the access window.

Re: Anyone know what this is?
 

Yeah,I can't visually match it to anything in the auburn product line.

Re: Anyone know what this is?
 

After hours of browsing summit it looks like it's a Detroit locker but I still can't get a hit on the part numbers. Any way to tell if it's a 7.5 28 spline posi? Take a look at the link and let me know if it looks like a match to you.

http://www.summitracing.com/parts/DTL-162C59A/

http://www.summitracing.com/parts/DTL-162C58A/?rtype=10

Re: Anyone know what this is?
 

Looks like it.
Start counting axle splines inside.

Re: Anyone know what this is?
 

Okay, so i counted the splines 3 times just to be sure and I came up with 28. So far I believe I have a 10 bolt 28 spline Detroit locker. I still don't know if it's for a 7.5 and i have no idea how to determine that. Anyone know how? Thanks for the help so far!

Re: Anyone know what this is?
 

Start up a chat or phone call Summit and ask for the o.d. where the ring seats.

There are only so many 28 spline apps out there.

Re: Anyone know what this is?
 

I called Eaton and they confirmed that it's a 7.5 10 bolt 28 spline Detroit locker for Gm 3.23 and up. I'm pretty excited seeing as I only paid $190 for it, a 87-94 4 bolt main roller shortblock, and a 400 crank. Now I have a new question. I want to put this in my 89 Iroc which was equipped with a 305 TPI and a 700R4. I'm pretty sure it has an open rear with a 2.73 gear in it. I know I need a set of Moser 28 spline axles and i'm swapping to a 3.73, but what else do I need for this swap? Thanks.

Re: Anyone know what this is?
 

I think there was an adapter to use a 2pc seal crank in a 1pc seal block since any 400 is a 2pc rear main seal.

New flexplate; 153 tooth let you keep the same starter.

Re: Anyone know what this is?
 

No, I meant what else do I need for the rear end swap?

Re: Anyone know what this is?
 

When you order the ring and pinion for the 3:73 gears you will also need to order an installation kit for the bearings, shims, crush sleeve, etc.
I believe with the axles you will need new axle bearings and seals. Even if you do not need them I would put new in anyways while doing that much work.
What are you doing for rear brakes? Is your current diff a 9 or a 10 bolt? If it is a 9 bolt then that carrier will not fit. I am assuming that you have already checked and know that you have a 10 bolt.

Re: Anyone know what this is?
 

Yeah, it's a 10 bolt thank god! I'm going to stick with the stock rear drums since I'll be doing alot of power brake burnouts. Lol! Hey, thanks for all the help.