Hey, what did you mean "bulge" between the bed floor and rails? Also, the propane would have to be mounted on the exterior. It would be really convenient to have one mounted on the inside but it would take up too much space inside (especially when every inch of real estate is crucial) plus the added risks.
If you were to draw a plumb line from the inside lip of the camper shell to the floor of the pickup bed you would see quite a lot of volume carved out of the walls of the bed. That space is a maze of bulges, bumps etc that I'm sure is a function of stiffening a bed with thin sheet metal, but it makes utilizing that area tough. I was able to tuck my propex furnace, electrical stuff, battery, etc a few inches into that area so that side of my box module only projects a couple inches in from the wheel well.- my goal is to have 48" clear between these "permanent" parts of my modular system. From your pictures it seems like you inherently have to ignore this space. understandable when your system is not unique to each vehicle. As for propane. having the 5 lb cylinder outside is a deal killer for me. At least on an Atlas its just in the way no matter where you try to mount it on the outside. Plus, I don't need to advertise my overlandy-ness with stuff strapped to my camper. I finally caved and built a propane locker at the back of the side box that seals and vents through a 1" hole I cut in the side of the inner bed. I followed Marine guidelines for the construction of the locker so practically speaking I feel okay about it. But as other's have noted here, try explaining that to the insurance company... hence it would be great to see someone professionally manufacture an interior propane solution that passes RV standards....
