Doing some more thinking...maybe attach the air shock absorber to the rear bumper using the available holes and building an adapter plate to bolt into there. The top of the shock will not be any higher than the top of the bumper so the tailgate won't end up hitting the shock absorber. This way there will be no welding required on the hitch! I would only have to build attachment points on the trailer and the truck bumper.
I did notice that the ballast weight in the trailer did okay but didn't do anything fer the road oscillations when I encountered those type of road conditions.
