See Figures 1, 2 and 3
The purpose of the fuel return system is to reduce high temperature fuel vapor problems. The system consists of a fuel return line to the fuel tank and special fuel filter with an extra outlet nipple to which the return line is connected. During normal operation, a small amount of fuel is returned to the fuel tank. During periods of high underhood temperatures, vaporized fuel in the fuel line is returned to the fuel tank and not passed through the carburetor.
The extra nipple on the special fuel filter should be positioned upward to ensure proper operation of the system.