I feel like since this is now used very much like a lighter duty truck, that going to a one piece 3 to 4in shaft would be able to work just fine as far as stiffness goes. And geometrically speaking the U joints would receive much less stress due to a shallower angle. I intend to swap to a 14 bolt anyways so I can also correct for the angle there as well. The only thing I would really absolutely have to do is replace the bearing for the output shaft of the transmission since that will be seeing more side loading than before.
