Thanks for the partial answer (genuinely, not being sarcastic). I had never been all the way to page 42 of the order guide before.
Looking at it the 4x4 is probably more what I need as far as capability. Plus no hoops to find out and then jump through.
Still curios how they claim that the 4x2 RCSB can come with the 3.73 & 5.0 in the "trailer and towing guide" but not let anyone actually buy it.