Measure the length and height, cut that out of whatever wood your using (I used 3/8" plywood.). Place the cut piece of plywood in the bed against the wheel well. Make sure you have it sitting in the right spot front to back, even between the front and rear posts. With the wood against the wheel well take a pencil, lay it on the wheel well and trace it out on the wood. Cut it out with a jig saw and you have your panel. You may have to notch the bottom corners but its no big deal. Just remember measure 2-20 times, cut once
. You can see mine here, start with post #820.
http://67-72chevytrucks.com/vboard/s...264226&page=33