Hy 1946GMCDAN, yes it does matter which terminal you mount the wires to, one terminal gets the ignition wire, and the other gets the wire to the sending unit in the tank, I don't know which terminal gets which wire, on some gauges there was an identifying tag to say hook ignition power to this terminal, yours may be gone. So you may have to find a manual with a picture of the back of the gauge, or maybe someone who knows for sure will chime in and tell us which terminal gets which wire.
