Raising camper height...wood/foam/rubber etc...

Depending on how much room you need, I'd use the plywood. On one camper I used a sheet of 3/4" and on another I used two sheets of 1/2" with some 2 X 4s in the middle for more room. The foam isn't a bad idea, but I can always use the lumber for someting else later. I never secured any of it to the truck bed - how can it go anywhere with all of that weight on top of it? And the camper is secured to the bed, right? - therefore the plywood can't move.

Bill