My 68 GTX has the 5/16 fuel line and 1/4 return line. I don't use the seperator just an inline fuel filter. The return line is not used. Car has the 2 vent tubes installed look to be orignal. 3 years car has been fine. Yesterday went for a short ride stopped to get a coffee and saw fuel pooring out under the car. Opened the hood and saw fuel coming from the return line. Never did this before. What could be the problem? I plugged it off with a vac plug to stop the fuel for now. Just wondering why it was coming out of return line.