I did an axel flip on our TT, it was the only way5200# would fit, and had sway problems. It wasn't the fish tailings most call sway, rather the flopping side to side with ruts in the road. I had both a smaller TT and a 3500 Dodge.
Most RVers do silly things with the hitches rather than face the fact it's a suspension problem. I learned that with a Cherokee and a tent trailer 30 years ago. On our TT, I solved it with anti sway bars. We had shocks on the TT so I didn't have to add those. That would be the first step, it may be enough. On the TT I used a 48"x16"x1" anti-sway bar and on the truck it's a aftermarket 1 3/8". I'm able to blithely cruise up the heavily rutted "Cog" at 120KPH, I also switched to Michelin truck tires. I use a truck camper in hunting season so I needed a sway bar on the truck. Remember TT suspensions are only one step removed from the wagons used on the Oregon Trail. Dodge when they widened the frame on Ram thought that they didn't need a rear anti-sway bar, they are wrong. Even running empty, she handles much better.
