I discovered a bad play on my output shafts coming from the diff and a small leak on the driver side seal.
Just because needs to be opened I'll use this time to install a 3.9FD and new plates with WPC treatment.

about the play on the output shaft (about .100 / .150" ) I guess the bearing are gone. how many chances also the output shafts are gone? (they are less than 300$ shipped) I don't want to waste 300$ in advance... or you guys think that is better to replace pretty much everything for peace of mind?

I just hope that isn't the diff completely gone