My 2007 longbed Prerunner has 4 'slots' in the ridge that runs the length of the bed walls (see attached pics, the slot is above the inverter). I was thinking of making up 2 planks (either wood or aluminum) that would sit in these slots to go across the width of the bed for carrying 8' x 4' sheets of drywall/lumber etc. The width between the wheelarches is less than 4' so an 8' x 4' wouldn't sit on the bed floor properly.
I wanted to make the top surface of the planks the same height as the ridge and wheelarches for maximum support of the material; if I use a standard 2" x 6" it will be too high unless is sand it down a bit.
Has anyone done this? If so, what material did you use? And how much load did you put on there?