The trailers pin weight plus other stuff in the bed and back of the cab can overload your F350 FRW 6300-6700 RAWR. RAWR = a tire/wheel/rear spring pack. We can't tell you if the rear springs are shot. I would say if its had a heavy truck camper on it all these years then I would think about replacing the rear spring packs ...or a air bag system.
Like any truck/vehicle you need to weigh the axles when loaded. Then decide what action to take.
I would also check with our truck camper forum as these guys/gals carry lots more weight 24/7 than the hitch load from a rv trailer.
