There is what appears to be a small plug on the bottom of the tank. That area is quite banged up. The line is hard from the tank to the fuel pump. The outlet on the tank is just under the seam which in this position lines up nicely with the frame along which the line runs. I was told by someone in a classic parts store that that is the right spot which would mean that 1/2 of the tank is below the outlet unless... there is a tube from the outlet that curves down towards the bottom of the tank to pick up gas from the lower 1/2 of the tank. The truck is a 47 second series.

It's a small world, but I wouldn't want to paint it.