Once again Roger has exactly the reference needed on his web page. Now I just gotta hope the "pinion flange shaft" is easily visible and still has the color code on it...
If it turns out one is a 4.3 I may just swap the other to 4.3 instead of both to 4.1. Minor difference but might as well. This would also be the time to get a 4.3 LSD if the rear is 4.1, hmmmm...