I think that I have finally figured this problem out myself.
If you have open differentials you have to actually roll the truck with both tires on the ground and compare the drive shaft rotations to one rotation of the tire. I don't know why, but if you have one or both of the tires off the ground it doesn't work.
If you have a limited slip or lockers, you can simply put it on stands and rotate the tires.
If your gears were as far off as the info that you are getting your truck would pull itself apart in 4wd.
