I can't see this one being right. Most people load their campers with 1000 pounds, and you need to count on the tongue weight of the trailer bearing down so far back of the rear axle, as well as the weight of the camper and it's center of gravity.
Sit down, look up the capacity of the exact truck you have, with the tires and axles, then look at passengers and trailer hitches, then weigh the truck so you really know how much you can put in the box. The center of gravity might be behind the rear axle with that camper...