Can someone please help me identify this rear end. It appears to be a GM 10 bolt but any additional information that anyone can glean from these photos would be extremely helpful.

http://i1292.photobucket.com/albums/...zpse1d4734e.jp

http://i1292.photobucket.com/albums/...ps8fae59f1.jpg

http://i1292.photobucket.com/albums/...ps5fdbd1b3.jpg
http://i1292.photobucket.com/albums/...pscb4c5c13.jpg

 

Need a picture of the rear cover.

 

First link didn't work maybe this will.

http://i1292.photobucket.com/albums/...psebcaf1e4.jpg

 

Looks like an 8.5 10 bolt, the squared off blocks at the lower corners of the cover give it away.
This is the one I am using in my truck, 70-81 camaro. 8.5 was used in just about everything GM from 1970. Camaros, chevelles, monte carlos, impalas, trucks, vans, etc..

 

How would I be able to tell what gears are in it?

 

For an open rear jack up one wheel only, other has to touch the ground and not turn. Turn the wheel in the air two times and count the driveshaft revolutions.
For a posi rear jack up both wheels, turn a wheel one time and count the driveshaft revolutions. With a posi rear both wheels will turn together in the same direction. If they do not then the test will not work.

 

The codes you've given are for the center section casting, they will not tell the ratio or application.

Look on the front passenger side of the axle tube for a Stamped code - it will give ratio and application.
For the info you've given the code will most likely start with a 'P' or a '2' ...

But to decode what you have:

The date cast code
C 17 1

C = March (Month)
17 = 17th Day
1 = (Year)


1254333 is the cast number. which means it's a 8.5" 10 bolt GM Rear end.

 

C = March (Month)
17 = 17th Day
1 = (Year)

Moe,

the 1 for the year is for waht year, 1971? 81?

 

C = March (Month)
17 = 17th Day
1 = (Year)

Moe,


The 1 for the year is for what year? 1971, 81???????

 

Doesnt matter, 71 and 81 used the same internals. Probably an 81 only because the 12 bolt was still around through 1972 and the 10 bolt was just being introduced to replace the 8.2 10 bolt in the early 70s. Didnt become as widely used until 1973.

 

I can not tell with the info given... the 8.5" 10 bolt was started being used in GM cars in 1970 (replacing the 8.2" 10 bolt) and started in vans in '75 trucks started using it in '80 (replacing the 12 bolt). So it can be a '71, '81 or even a '91. you can narrow it down some by the Assembly Stamps I spoke of in my other post.

 

Thinking of getting a 8.8 because I see so many on the board go with that rear end. I found one out of a 02 Ford Exploerer Sport with disc brakes. Does anyone know if this will work for my application (49 Ford F1)