I think that we are talking about different offsets, I am referring to one of the axle tubes is approx 2 inches longer than the other, on mopars the axle tubes are the same length.
We are talking the same, just different. Ford makes one side longer than the other to give it an offset, so does stock mopar car Dana 60. And you are right, an 8 3/4 has same length axle shafts, but a 1 3/8" offset is built into the center section.