TxGearhead, I ripped down two full width 2x4's to around 3" wide, then stacked one on top of the other, they are 1/4" less then the width of the bed. The reason for two is that the bottom of the Bigfoot has about a 1/2" radius in the bottom. I then screwed the guide blocks to the vertical (rearward) face of the 2x's with 5 1/2" long torx head wood screws. The outside dimension from block to block fit snug to bed and the inside dimension is snug to the camper. All contact points between wood and camper are covered in felt.
The front blocks were easier to secure as they just sit on top of the 1 x8 (full 1" thick) which spans the width of the truck. The 1x8' took a while to fit as on my GMC, the bed is NOT flat from side to side, the ribs are higher on the outside then the middle which required the bottom to be tapered. In addition, the sides of the bed are not square but taper front to back where the wedge contacts the side, I just inserted shim shingles cut to fit the slight taper so the wedge contacts the side of the bed.
Next as I have to raise the camper 1" to clear the tailgate opening, I have a full sheet of 1" poly Iso foam in the bed which is flush with the 1x8. The foam extends to the front of the bed. I then put my rubber bed mat on top of foam and 1x8 and the front wedge assembly sits on top of that. As I use my truck as a "work" truck, I can leave the foam, mat wedge assemblies in my truck all the time. I did have to cut the foam 1" shorter where it meets the rear assembly to allow for the tailgate to clear, I just save the strip of foam so I insert it when the camper goes on the truck so that the 1x8 is flush with the rear of the bed.
Long answer for a simple questions, a few pictures would be worth a few thousand words.
