I bought a 1990 Gmc k1500 4inch suspension and 2inch body lift,5 speed for a Grand,all i got to do is put the clutch in. When i went to get tranny fluid they said i had to go to the dealership they don't carry it. Whats up with that what can i use?

IIRC you need to use synthetic oil in it. My neighbor has a truck like and had a nice leak to it, kept bitching about the cost of the stuff....

i run regular 90 w in mine and its got 240k on it so far with out any problems