What’s the reason for srw, you driving it daily when not towing? Dually is much more stable when getting that heavy. I’m looking at a toyhauler that has a max weight of 17k so that would be 4K at the pin. I see guys pulling with srw 2500 rams with 32” tires, 42 footers. The ratings are all over the board with the manufactures. I think you need to look who’s towing what down the road, or go to a rodeo and see what is the most popular rig. #1 Ram, #2 Ford and not many chevys. I guess for me it would be a 450
