Truck towing question

I got my first travel trailer in 78 a 24ft Prowler.Towed it with a W150 Power Wagon.400 big block with a auto trans.It was a great truck.Only problem with that truck is it rusted away in 3 years. Later I had a 1500 4wd Chevy 350 pulling a 28ft Prowler 5th wheel.Again did it's job and then some.
Now I still have a old 88 D 350 dodge 8500 GVW and weighs 4800 empty.Automatic 318 with 4.10 gears. I tow a 24 ft enclosed car trailer with a weight of 7000+ lbs.It too gets the job done.Old trucks "work" and you can fix them with a hammer and a screwdriver.