I have a sierra rear diff here how can I ID it to see what else it will fit all I know is it is a welded diff

 

Is there a tag on it?

 

Don't think so mate

 

you could count the teeth ?

 

I take it is has bolt on shafts and not push in?

What's the diameter of the face that the shaft bolts onto?

 

I don't know either lol I think they are push in

 

If they are push in shafts the diff is from a standard Sierra, hard to say which model as it could be from a basic 1.6 or, for example, I have a 2.0 Ghia that has the push in shafts type diff.

If your going to sell it just advertise as

'welded diff, from standard Sierra with push in shafts'