I drove the 59 from Ca when I moved to GA in 1982 pulling a biiig U-Haul trailer. Only problem I encountered was I ran out of gas between Kingman and Flagstaff but only about a mile from a station. Luckily I had a 5 gal gerry can and dumped it in the tank and cranked her up. Mileage was way down from the normal 11-12 mpg because of the weight and mountains climbed.
My son and I drove the same truck from here in GA to Santa Barbara and back this last June, man what a blast we had and I highly recommend the experience. We lost the bearing on the generator in Albuquerque. Local Carquest had a rebuilt on the shelf but two days later the bearing in that one went south in Flagstaff. Had to spend the night waiting for a replacement to come out of Phoenix and all went well from that point until we got back to GA on July 4. Averaged 11.6 mpg on the entire trip with only a few items in the bed.