The only thing I am sure of is that it is pretty confusing. Seminaryranger and I had a little discussion about the super 60 front axle when I wasn't sure I had one.

He posted a link for an article - I think it was from 4 wheel offroad and it said the Dana 60s use 1480-series U-joints (SPL 55) that are 4 3/16" in diameter and the Super 60 used on '05 and newer F450/550 has 1550-series U-joints (SPL70) that are 5". It also stated that because of the larger u joints, the Super 60 uses larger greaseable ball joints.

With the larger ball joints I am assuming that the castings for the ball joints are bigger and farther apart and only work with the bigger brake assembly and the 19.5" rims and won't work with the smaller brake assembly and the 17" rims.

The bottom line is that I am still confused and really don't know what is what. So you maybe right I don't know.