I've got an '01. 5 with the 5 spd, and recently had to replace the pinion seal on the back rear end. When I bought the seal and nut, I was asked if it was a 70 or 80, and the parts guy looked rather surprised that I knew right off the bat when I said '80'. Got the parts home, did the seal and nut replacement and everything was fine. Guess it really must have been an 80!