I have the same truck and have found from my research
mercon V for the tranny & t-case
80w 90 for the front diff
85w 140 for the rear
and i am gonna be running full sythetic Amsoil ATF & gear lube in all those
(especially the tranny since i have heard and seen that the sychronizers like to go in the ZF models)
I've got most of the fluids gathered up but haven't had a chance to change them yet (only had the truck for 3000 miles so far)