Thanks to everyone who commented on my post. I decided to install a Dana 70hd in the rear drive. It has a 3.73 gear, which is awesome for drivability. I May install a 5 speed direct for more usable gears. I pull a 16 foot flatbed from time to time loaded with logs or lumber. I am not sure how the truck will pull going from a 6.17 gear to a 3.73 gear. Of course the tall 37.5 inch tires will be replaced with a bfgoodrich all terrains 33x10.50 16s. According to my math at 65mph I will be turning approximately 2500ish rpms.
