As stated only you know what you want. I drive a truck that GM designed for highway speeds when I'm in a hurry. I went with C and I stay on the backroads too. In my 1-ton, 45MPH already feels like 85 but the 3rd member swap was too easy to ignore and donor trucks are laying around everywhere you look. I think I'd have to replace everything from the steering box down in order to feel safe over 45, but then I would no longer have a vintage truck!
