Lets discuss fuel return lines. Through my reading and talking to other car guys it seems like a fuel return line may be a good addition to an old car. I personally don't have an educated opinion yet. My area of concern is a street car with carburetor, mech. or elect. fuel pump. Percolating and vapor lock seem to be reasons for a return line. I have a 1969 blah blah car with a factory return from the fuel filter. I also have a mechanical fuel pump with a provision for a return line, and a Holley pressure regulator with the same provision. SO do we need them? If so how should they be plumbed? Thanks!