I have a Forest River Sunseeker 2300 on an E450 chassis that weighs 9900lbs empty against a 14,500lb GVW and that big GCWR. I can tow pretty much whatever I want and have. The usual hitch-up is an enclosed 20' trailer with a race car inside along with other "stuff" that weighs in at 7500 to 8000lbs. My GCW is usually right around 20,000lbs. Bought new off a a dealer's lot based on the small house and heavy chassis, it has 17,000 miles on it and handles the load just fine. I did do the normal Ford add-ons of Bilsteins, a larger front anti-roll bar, and an alignment, and it got even better.