In your original post you stated that the pin box is too close to the bed rails in tight turns. Flipping the adapter will solve the issue. You have a new 5th wheel so I doubt that making this change will cause issues with the front cap making contact with the cab of the truck.
I have a short box Ram 2500 and also use the Anderson hitch. I flipped the adapter, moving the ball behind the pin which solved the issue of getting too close to the sides and tailgate. I also raised the pin box one notch to level the trailer and I still have 6" of clearance between the bed rails and the trailer.