8.5 rear end identification

[Travis Clark]

Hello all,
I just recently purchased an 8.5 rear end to overhaul and place into my 79 El Camino. The identification numbers appear to have been worn off possibly by exhaust pipes. The only visible information available for identification is GB______E. In order to order a new carrier and upgrade the gears I would like to know what model/year range this rear end was originally installed in. Any help would be greatly appreciated.
Upon further investigation I found #3969277NF and another stamp #GM66 this information leads back to a 1971 Chevelle
http://www.myss396.com/ChevelleInfo/Differentials/1971_Differentials.html

Has anyone used one of these rear ends in their G-Body?

 

[pontiacgp]

That looks like an 8.2 with the 8.5 cover on it. That rear end is 4.5" wider than the G body rear. You'll need conversion uppers and you can use the stock lowers. I bought my conversion uppers from UMI for my 8.2 out of a 67 Chevelle

 

[Travis Clark]

That looks like an 8.2 with the 8.5 cover on it. That rear end is 4.5" wider than the G body rear. You'll need conversion uppers and you can use the stock lowers. I bought my conversion uppers from UMI for my 8.2 out of a 67 Chevelle

Roger that Sir, thanks for the information. Of course I was told that it came out of a 1980 El Camino. Onward and upward.

 

[pontiacgp]

You can check the pinion nut, an 8.2 is 1 1/8" and the 8.5 is 1 1/4"

 

[Travis Clark]

You can check the pinion nut, an 8.2 is 1 1/8" and the 8.5 is 1 1/4"

Roger that, I'll look into it as soon as I can to verify. If the pinion nut is 1 1/4, the axle tubes are still too long correct? So in order to use it if it is an 8.5 it would have to be modified in regards to brackets and axle tube length?

 

[pontiacgp]

and if it is an 8.5 it will have these ears at the 5 and 7 o'clock positions...

 

[Travis Clark]

and if it is an 8.5 it will have these ears at the 5 and 7 o'clock positions...

I can take a picture of the bottom of the housing but it appears to have been grounded off. The area on both of those areas are rounded out as if done after market, not in line with the original shape of the housing.

 

[pontiacgp]

I don't understand why anyone would grind those ears off.........but not much surprises me anymore

 

[Travis Clark]

I don't understand why anyone would grind those ears off.........but not much surprises me anymore

Beats me Sir, I thought the same thing when I was researching the 8.5's and felt the indentations at those locations. Purchased it from a circle track guy in San Jose, he seemed legit and had lots of parts around his place.

 

[pontiacgp]

If you have your G body 7.5 rear why not compare width measures of the two rears. Also I'd suggest you remove the cover to see if the spider gears are welded together. I worked on a circle track team and since we were not permitted to run a posi or a spool we welded the two pinion gears to the side gears, commonly known as the spider gears. I don't know any circle track that allows a posi and with that rear end it must have been on a lower class division so I doubt it has a spool. I would also check the right axle that takes all the load in circle track for a groove in the axle caused by the axle bearing. Also lay a straight edge along the axle tube to make sure it has not been bent bouncing off a wall. Then after you do that you can always sell the gears to the circle track guys cause it would be the right gearing for that tack.