They make receiver hitch extensions that will allow you to tow your trailer with a camper that extends a modest amount past the bed of the truck. I used a 2' extension on a Ram 3500 dually that I carried an Arctic Fox 995 camper, and towed a 16' enclosed trailer with. I had no problems from the hitch extension. The extensions do decrease the towing capacity of your hitch though. On mine it stepped down from a 2 1/2" receiver hitch to a 2" receiver hitch, and I believe it decreased the capacity of the hitch from something like 12000 lbs to 10000 lbs. I could be off on those numbers a bit, because it has been a few years since I used that set up. It will say on the extension you buy.
