It comes from a '88 sierra 2.0L


[img]Gax rushCIMG0761.JPG[/img]
Rescued attachment CIMG0761.JPG

That’s just the casting number so wont give you any info on what ratio it is! There should be a small tin tag attached to one of the bolts on the rear of the diff, this will have a letter on it that relates to ratio. It is also marked on the cars vin plate!

Probably a 3.62 non ltd slip

[Edited on 30/4/06 by pathfinder]

is says 83BG 4033 BA

You may find this site useful http://forum.fordsierraclub.co.uk/viewtopic.php?t=5843

the other mounting holes might have been usefull if straight thru 7 inch if threaded odds are 7.5 inch therefore no use on an indy

There's another line of numbers on the little tag. They'll tell you the diff details.

Just turn the diff input flange and count how many revolutions it takes to comple one rotation of the output.