Assuming new truck and new camper.
Lance 855S shows a "wet weight" of 3084lbs. Assuming that means with full fresh tank and propane, but nothing else like food or your stuff.
That's an awful lot for an F250. A typical F250 has a rear axle rating of 6084lbs, limited by the tires, and weighs in the neighborhood of 2800-2900lbs empty. So with just the bare essentials, you will be exceeding your tire ratings right from the get-go.
At the very least you will need some sort of suspension add-ons, and bigger tires right off the lot. To me, it's ludicrous to throw away brand new tires off a brand new truck, when you can just get the truck with the right tires to begin with.
If you upgrade to a single rear wheel (SRW) F350, you will not need the tires at least, and may not need suspension add-ons.