We got this Dana 30 out of a high mileage 1984 XJ a few years back.
I ran it in the Molly Mule (Red 1988 XJ) and then in the Tweety Jeep (Yellow 1989 XJ).
I put a lot of off road miles on it without ever having problems.
Here are the pictures of when she finely broke.
We just thought it was the R & P until opening the cover.