I had a 2008 PRO-4X and towed a 25 ft. BigFoot which weighed 6,000# loaded. The rear drooped 3" upon initial hook up which was remedied with a Reese SC hitch with anti-sway. I also put on air bags to level the truck the extra 1" after dialing in the hitch, took 20# of air. The truck pulled that trailer very well with never a hint of sway. Make sure you have a good brake controller and TT brakes are adjusted as the Titan brakes could get overwhelmed (might have been upgraded). The 5.6 had plenty of power to get the job done although it had to be wound up at times which was no problem. Safe travels.
