I can't understand why there are so many people who think they can pull larger loads than the chassis is rated for without problems and complications.
The maximum trailer capacity Ford certifies the F53 chassis is for 7,000 lbs. That's for the smallest 16,000 lb. GVWR chassis. All other chassis are rated for 5,500 lbs. or less.
http://www.fleet.ford.com/resources/ford/general/pdf/brochures/2014/Class_A_brochure-2014_LoRes.pdfThis isn't the motorhome manufacturer derating the towing capacity because they add frame extensions. This is the maximum towing capacity rating Ford gives the bare chassis.