sambo42xa, fact is your truck should be quite capable of running 55 plus mph if it's in average good condition. What does average good condition mean? The brake drums have been pulled to verify shoes and wheel cylinders are good and they do work as designed. Steering, if you hit a bump it's no big deal. You don't have to fight to go straight down the road. The engine starts every time with no drama, no strange noises or smoke. Truck never overheats and coolant hoses have been replaced in the last 20 years. Tires are less than 10 years old, better is less than 5 years old.
If I had a truck that clicked all the boxes above, on a good road I'd drive at 50mph a bit, no issues then 55, then 60.
Watch the gauges, stop if oil pressure drops or it starts overheating.
That's what I'd do.
Good Luck!
RonR
Last edited by moparguy; 03/08/2022 2:49 PM.