I'm trying to figure out what my rear end is. It is a 9 bolt and the tag on the diff says 2.77 for the gears. I don't know what year it is, and it isn't the stock rear end. There is what looks like a part number stamped on the tag also, but I cannot make it out. Also there is another tag that says something like "Spin Resistant Diff" would this mean posi? What other way is there to tell who the manufacturer is?? I was told it is a moser 9 bolt. I don't think this is true...but I don't really know how to tell. If anyone can help me out I'd appreciate it.

 

9 bolts are made by Borg Warner in Australia. Nobody else makes a 9 bolt. Posi is actually a GM name for a limited slip differential.

9 bolt info
www.diffsolutions.com

 

sweet thanks...

I tried a site called 9bolt.com but it appears to be dead.

 

9bolt.com and diffsolutions are the same IIRC

The rear end should be a 88 or 89