Diff. swap-out 90 300e 4MATIC
 

I am going swap out the squealing diff in my '90 4mat.

A new one is insanely priced so it'll have to be from a re-cycler....I found one from a '93 4matic at a good price, so the question is....

Does anyone know: Are the diffs from these 2 year models compatible? and how big a job is this, hourly-wise?

Thanks in advance!