I'm removing the original behind the seat gas tank in favor of the original under bed tank. I was able to locate the whole setup from another Ford truck guy over at www.ford-trucks.com. It's not in the best of shape but it's restorable.
The first step for me was to fit the tank into position. I had no idea how it was oriented but it was reletively easy to find the mount holes. I left the bed on for this during disassembly so I could locate the new fuel inlet in the bed side. The tank was loosely mounted and a hole was drilled in the bed side where I will locate a gas door.
The tank itself was then sandblasted. I then cleaned the inside using some industrial cleaner called 'Marine Clean' and a bunch of rocks inside for aggitation. If I was to do it again, I would use a chain inside instead of rocks because they are hard to remove. After cleaning, I checked the tank for leakeage and found two pinholes.
The pinholes in the tank were fixed by soldering them up. After the inside was dry, we coated the inside with an alchohol resistant coating from JCWhitney.
The tank and shield were then mounted in the chassis. This turned out to be a little difficult since I was missing some mounts. The rear tank mount was installed as original. The front mount required making a new strap and adding a frame crossmember. I believe there must have originally been a crossmember but the guy I bought it from probably didn't realize it was added only in trucks with the auxilary tank. I was able to attach the shield using the original mounting configuration. The dark spots on the shield are where I used Chassis Saver to cover the attaching bolts. I'll be covering them with a closer color later.
I will update this page further when the tank door is installed.