Fuel Tank ?

I'm putting my 86 700F back together after the repaint and I can't seem to figure out where the fuel lines go... There are two openings under the tank but only one input on the fuel pump... Is the other a vent or over flow? Or am I missing something. When I took it apart I couldn't tell where both lines ran and the one on the right side popped off before I could see where it went to.

Does anyone know where both of the lines go, and which one goes where?

Thanks
J.B.