markowwes wrote:
Your camper sits over top of the truck frame rails so you don’t need a heavy deck frame.
You would be surprised how much a 5500 frame flexes. If you do any off-roading, I suggest a heavy deck frame. I cracked a TC frame off-road (in a normal pickup box, with Torklift frame ties). Had to pull the bottom of the camper and build a steel subframe for that corner.
After that, I pulled off the truck bed and replaced it with a heavy steel deck, that had much less flex in it. When I got my 5500, I checked the flex on it and was amazed at how much I could get it to twist with bare frame rails. I run a heavy steel bed on it, and it still twists to the point of visible deflection when I lift a tire.
If you stick to paved roads and freshly graded dirt, it probably isn't an issue to rely only on the frame rails to provide a rigid surface... YMMV. I would be skeptical to, but it all depends on how you use them.
Also, not sure how the Ford F550 and Ram 5500 compare in this regard. I believe both use similar C-channel, so should be pretty close, but could be a non-issue on Ford for some reason.