OK….so no experience with slide in truck camper, but if you’re going to raise it 7” that seems like an awful lot of wasted space.
I did build a base, drawers, and side boxes for my Topper. And While I used 2X 10’s it would just be a scaled down version.
A 2X6 has a nominal width of 5-1-4” and a 2x8 has a nomianal width of 7-1/4”. I made box cuts for 1X’s (3/4”) to be flush with the top.
Then you could attach 1/2” plywood on the bottom to keep the 2X runners secure. Still need a little more height? Add a piece of Styrene closed cell foam board under the base which will add height and add a thermal barrier (which I also did on mine).
dcpd6wotaa0mb.cloudfront.net
(It’s some tough stuff, check the specs….25lbs compression psi per square inch
1 square foot is 144 square inches-
25 X 144 = 3,600 compression psi strength per square foot. I have it under my concrete- radiant floor heat system)
Some custom shallow drawers would store an awful lot of small items IMO…….. but otherwise it might give you some ideas.
Three 2X runners the length of the bed would be more than enough, then given that shortness of span between the 2X’s (across the 1X supports and the number of 1X’s you add reducing that span and you’ll be able to achieve the psi load per square inch that you need. Mine is built with quite a bit of overkill, but I’m a welder by trade…… that’s how we roll
Hope it helps, Glenn
(Post Edit: I forgot to mention, I would also box in the end towards the (attaching all 3 runners) cab……which leaves the end towards the tailgate open for drawers or to slide in material.)
