Consider the condition of the camper floor pack and framing. If it isn't up to snuff, you may be better off rebuilding the camper to fit your truck bed. I rebuild a 79 Grandby to fit my 2016 Chevy. Here's my build. http://www.wanderthe...= 1979 granby It's not near as detailed as Pokey's or Tim's.
Yes, the wood structure Is something I am just now learning about and need to look at very closely. If it looks weak, I might remove it all and re-structure it out of welded alum or light steel. I had always planned to fabricate a new bed, so the larger awkward size is kind of a bonus. Used campers that fit modern trucks were just out of my budget.
The big reason I decided to eliminate the standard truck bed is so I can get a much more secure and quick release mounting points. I will use this for pretty hard off-roading. The plan is to be able to pop this thing off the truck very quickly at camp if needed. yes Kind of Odd.
Thanks, I will go read your build. Is yours done?