Thanks for the help. I went back out today, determined to locate the threaded hole for the screw that the ground wires are attached with. It's on the driver's side behind one of those heavy vertical pieces that are welded to the main frame. The welded verticals are put there to serve as mounting "posts" to attach the bed. I think there are 4 total - 2 right behind the cab, on either side, and 2 right as the frame bends upward to allow the axle a space to move when it hits bumps.
These ground wires are insulated and come out of the disc that covers the hole for the fuel pump, and gage electrical stuff. One group of the wires that come through a rubber /plastic plug in the top of the disc are plugged into an existing waterproof socket, the wires going to the instrument panel and the fuel pump relay under the hood on the firewall. The other two insulated wires screw to the frame as mentioned in original post. The fuel tank has no bare copper wire grounding it to anything. Those insulated ones must serve for that too. The tank has rubber insulation strips that absorb vibration, and act (maybe not intentionally) as electrical insulators between the tank and support straps. Anyway, I'm moving along. Tomorrow, realign the truck bed with the holes in the frame, and finish.
Tuesday, October 8th, 2013 AT 11:57 PM