I have a 2014 silverado 1500 with upgraded 10 ply Lt tires (275/70/18) My tt is 28 foot weighting 6800 loaded. I have a wdh and friction sway bar When I tow and it's breezy outside, I can feel ...
Well, you could air up to the 80psi max of 10 plies, but it's possible your wheels may not not go that high. I've seen alloys that only go up to 60psi, and that's pretty much the max I use.
But it could be just the usual sway from the trailer nudging your truck in windy conditions. I too have a single friction bar. But could probably use more. Thinking about an Equal-I-Zer ...
EDIT: I would go up to 60psi and see if that helps