Your F350 srw has a 7230 rawr that will be carrying most if not all of a trucks campers weight.
These trucks rigged out like you say rear axle may weigh in the 3500+ lb range leaving around 3700 lbs max for a truck camper. I sure wouldn't exceed a tire/wheel or rear suspension rating. Add 4400 lbs in the bed over loads Fords 7230 rawr.
That 4400 lb number is a gvwr payload and based on using the truck front and rear axles. Truck campers sit in the bed and add little if any weight to the front axle.
GVWR payloads are better suited for lets say a work truck for a business that requires a over head rack that sits in the rear of a pickups frame/in the bed.... and on the trucks front frame rails. That way all 4400 lbs can be distributed on fawr and rawr.
A 3100 lb truck camper ?
By the time you load the camper out like you want and road ready it may weigh over 4000 lbs.
Your looking at a one ton drw for weight carried in the bed like a truck camper.....or a lighter weight camper.
Or mod the F350 srw rear suspension with 19.5" tires/wheels and air bags/etc.
