putting a Kodiac camper on Ford F350 ideas

funny, I ran 2x10 with 3/4 plywood the length of the bed, worked to get height right but camper would slide to one side in wind, its funny I stopped to reset it and it took less than 5 mins to get blown back over, with no wind it centered itself no problem

its away now but thinking next year making a mold of plywood with a 2x6 cut down the center, it gives me little over 2 1/2 tall with 10 or 12 inches between, the plan the guys that make rubber paving and sidewalks here typically have some product left and would fill the mold, once set I have a couple rubber blocks 10 x 2 1/2 thick 8 feet long, use these for spacers its not slippery so should do the trick moving forward