All I have gotta say is HELP!

I am new to the world of rear ends and am trying to positivly identify a rear end I picked up. Here are the details I know.

It is a 10 bolt, axle code 6EW. I was told it was out of a 87 GTA, but the source I found for rear end codes etc said it was out of an 84. The diff is an open diff and has 3:23's in it.

I found the following link which sheds a little light on the GM 10 bolt and identification, but I am not 100% positive which one I have, but I am about 90% sure it is a 7.5/7.625 rear, check out the below link

http://www.prestage.com/cars/gm_10bolt.asp

Can anyone help me out with things....hopefully this is a real easy one and somecan can tell me that the other two types were not offered in thirdgens or something like that. I will also say my diff does have those little "small pointed ears at the bottom of the housing"

Help.....please!

 

All third gen 10 bolt diffs are 7.5/7.625" ring gears. The parts are interchangable. It's just the ring gear size that's slightly different. Even though it may be 7.625", it's still usually considered a 7.5". The performance option in the late 80's was the Borg Warner 9 bolt. It's completely different internally and uses a 7.75" ring gear. Parts are not interchangeable with the 10 bolt.

Somewhere around 1986 or 87 GM upgraded from 7.5" to 7.625". In 1990 they upgraded the axles from 26 spline to 28 spline. In 1993 (fourth gen) the diff was widened 2" on each side but is still a direct bolt-in to a third gen providing the proper offset wheels are used.

Since all third gen diffs are interchangable between the cars, the best way to tell what gears are in it is by pulling the rear cover off and count them. You never know if someone swapped the diff. There's a good chance the oil needs changing anyway.

I can't find a listing for 6EW

 

Stephen...thanks for the info...I thought it was a 7.5, 7 5/8's, I was reading somewhere that the switchover between the 7.5 and the 7 5/8's was in 85 but not 100% sure (I can call it up if you want)...and I was talking with Summit tonight and looks like the parts are interchangable between the two.

As for the 6EW code...I know it seems to be a slippery sucker. I might have actually messed up the code a little bit when I took a grinder to peel off all the dirt/grease/rust on the diff, so it may not actually be a 6EW code, maybe something different, but the stamping has been altered as a result of my "light" grinding.

 

7 5/8 = 7.625. That extra 1/8" doesn't make a huge difference with that tiny ring gear.

The code on the housing doesn't mean much since everything inside the diff can be changed.

 

Wouldn't it be nice if GM put a 8.5 rear in our cars in the first place.
Man that would Have saved us alot of cash buying after market rear ends.