My 70 SS had a new gas tank when I bought it. Two gas lines run from the fuel pump to the tank. There are 2 lines, one 3/8" and one 1/2", on the right side of the tank that run up under the trunk and are open ended. When the tank is filled and driven a few miles, gas vents out the larger hose. Where are these lines supposed to go or can they be plugged? If plugged, will the tank vent through the gas cap then?