50 owners should correct me if I'm wrong, but the 54-55 AD 3/4 ton front spindles are the same size as 1-ton, larger than the halfton with no interchangable parts from the frame down. I have not seen any bolt-on disc conversions for the 3/4 or 1-ton AD's, but I'm sure I haven't looked everywhere yet.
Any help from the other 'bolters?