I have a 2017 6.4 2500 3.73 longbed and just pulled my 24ft TT on the trucks first long trip with it which probably weighs about 7500 when loaded and it pulled it great. There was a couple good hills where it ran at 4500 rpm but it kept me at speed.
A couple times i was using the manual shift to lock it out of higher gears if I was climbing a hill and it was in a gear that it liked. I got about 9.7 pulling it. For only pulling a trailer a few times a year this truck does perfect for what I need it for.
When I retire in 14-15 years I will go back to a diesel again as we will likely travel alot more.