I agree, but the 28 splines are about the same of an upgrade as an 8 1/4" because the 28 splines are just the 7.5" axles put into an 8.8 ring gear (similar to the Ford Dana 50 that they came out with). It is personal preference, and I figure that for the price and work involved, I would want the 8.8 for my piece of mind.
I do not believe that the Ranger came with rear disc brakes either, but they did have a limited slip in some models