Vibration

Have you checked tire balance, bent wheel, and broken tire belt? Was it aligned after replacing all those parts?

Time for an inspection at a tire and alignment shop. In particular, have the mechanic measure the ride height. If the rear is low due to sagged springs, the drive shaft angle will decrease. That can shorten the life of the u-joints and can set up a high-frequency vibration.

If the truck has been raised, also look at the u-joints to see if they're binding.

Jack the front tires off the ground and spin them by hand to look for signs of a bent wheel. Jack the rear tires off the ground and run the truck in gear. If the vibration can still be felt, that leaves out anything in the front. A glass of water on the dash board acts as a nice vibration indicator when it's harder to feel that vibration when the truck is jacked up.