And the GCW includes a trailer weight. Probably 2500, 3000 or 3500 pounds. Adding axle capacity, dry hitch weight and trailer weight should get you close top that GCW rating.
2016 Jayco Eagle HT 29.5BHDS (ordered 12/30/15, delivered 3/8/16)
2015 F-350 crew cab, short bed, 6.7L PSD, Pullrite Superglide 3300 hitch