okay this is hard to explain, i have two 1977 ford C6 automatic transmissions, one is a 2wheel drive and the other is a 4wheel drive and the 2wheel drive tranny is rebuild but i need the 4wheel drive tranny and the 4wheeldrive tranny is worn out, i also have a non-married transfer-case so i thought i could get away with it, but i can't, and because the tail housing is longer on the 2wheel, so is the internal output shaft, and on the tail-housing piece on the 2wheel drive there is no place to mount the 4 wheel drive linkage so i can't use the 2wheel drive tranny so i'm left to do this, swap out the insides........ all i want to know is, are the in sides all the same? and the only difference is that the internal output shafts are different lengths?and the tail housing are different? ,,,,, how hard would it be to swap the inside apart?