You sir, are in a pickle. This is the hardest decision you will ever make with your rig. And getting it wrong is a nightmare. Ive seen guys that knew what they were doing and still hate their trucks after new gears. Others love them.

If you only got 4 tires on craigslist, I say, just run 4.

You will not change a 37" tire on the side of the road. Go with that streamline tail with no tire.