How to improve ride on my F250Silvarado Cummings DuraStroke?

Unless I missed it, you did not say what your towing I assume a TT. If your TT is loaded out of balance, that can add to the bouncing. Tail heavy TT like a fulcrum will lift the tongue and that gets exaggerated over bumps. Our F250 was a bit of an issue with the steering death wobble. I swapped out the OEM Shocks for Bilsteins 4600 on the corners and the 5200 steering stabilizer. Made a difference.

Hope that helps