I have the 4" Smokey Mountain and run 33x10.50x15 BF Goodrich AT. Rides good on the road and does well offroad. My tub and fenders are not cut. No issues with rubbing.
Turn backwards so it's not a scoop towels or blankets against the trailer rail. Tie down across the top and from the front to the rear of the top to trailer rails. I have done this several times with no problems. No damage to the top or the tubes. Don't drive like a maniac!!!