I would guess that 22R is somewhere around 9,000#, give or take a few hundred pounds. It looks like with the 5.4L engine, there is only a1,500# difference between the GVWR and the GCWR. The V10 has the full 7,000# difference that Ford rates the cab and chassis for, but I would assume Itasca rates it for 5,000# towing, with probably a 350# tongue weight limit, which naturally wouldn't be a concern pulling a toad.
2014 Itasca Spirit 31K Class C
2016 Mazda CX5 on Acme tow dolly- 4 trips ~ 5,800 mi
Now 2017 RWD F150 with a drive shaft disconnect