The SSR-610-40 Blue set was what I needed to help with no sagging and a smooth ride while pulling my 28ft travel trailer. They also help with no sway from the truck without a load. My truck still rides nice in town, on the highway, and off-road. It just feels more stable not rough.
I also have a new Bilstein 6112 adjustable Suspension leveling kit set to 2” front with 1” added to the rear. I have about 2,000 miles on my truck with this setup and so far I’m satisfied.