The Diesel dually suggestion was only a little in jest. If I were planning to tow a 5th. wheel travel trailer, that's precisely what I'd choose, and after over 40 years of towing all manner of camper rigs, race car trailers, construction and farm equipment, and 18-wheelers, I think I can speak from experience. GM doesn't make anything, gas or Diesel, that can run with the turbo Cummins on a power vs. fuel economy comparison, certainly not the Chevy/GMC V-8 Diesel.
A properly set up modern 3/4 ton truck with heavy duty tires would be the bare minimum I'd consider for the job at hand, or a shortened-wheelbase 1-ton stovebolt with V-8 power and completely modernized running gear and disc brakes all around, if there's some reason to go with an older-looking truck. I pulled a 22-foot Norris bumper-hitch camper behind a 59 Burb many years ago, and even with a 307 V-8, a SM-420 4-speed, and a Dana type 60 rear axle with 3.78:1 gears, it was underpowered and dangerous.
Jerry
