Your dimensions look like it should fit. You will need something to keep it from sliding forward too far. This will give you about 14" of storage space in front of the camper. I really don't see COG being an issue with an F550 unless you get a really huge heavy camper. Even if the COG is behind the rear axle you can still haul the camper, it just unloads the front axle a bit so the ride isn't quite as nice. My camper takes about 500 pounds off my front axle but there's still over 4,000 pounds holding it to the pavement. I've got thousands of trouble free miles with the rig.
