i see no problems with what you want to do D. Mick.
most people who say “you will be top heavy”, “you will flop it on it’s side”, “you will hit bridges” have usually never driven a lifted truck and camper.
i drive a very lifted K30 crew with 42″ tires and haul a 8 footer TravelMate for over 15 yrs with zero problems.
when your truck is that big, most people don’t realize just how heavy they are, i call my K30 my “Four ton Honey”, comes in at 7800 lbs with half a tank. just my axles, tires, t-case, trans and b block is over 3500 lbs, the weight of a small car, and that weigh down low makes you very stable. about the only way i could get it to be “floppy” or “tippy” is if i loaded 2 or 3 thousand pounds in the overhead bunk and tried turning hard right at 80 mph… and if you pull a trailer as well, even better. our quad trailer is close to 4000 lbs and it acts like a big stabilizing anchor on the truck.
you will prob find your biggest prob is the same as anyone who takes their TC seriously off road, WIDTH. i’m a shade over 12 feet high and have never hit anything, other than dragging threw tree branches on some goat tracks.
i was going to suggest slightly wider 41″ tires, but as the 550 has a 92 track, you got no worries.
may not be what your looking for, but have you looked at Phoenix Campers?
custom built off-road campers, guy from FWC left them and started Phoenix, so he knows what works on off-road tc’s. buddy bought one 2 yrs ago, little over 16 grand, but it is an awesome off road camper. all alum so it won’t turn to kindling bouncing around, and the best part is you can pick any width. buddy’s camper hangs out approx 3-4″ on the sides, you don’t even need to change your mirrors