Many classic and muscle cars were built in an era when automakers used open vents to allow air into fuel tanks. These vents were often hidden over the fuel tank, or up along the fuel filler neck. Back in the day, this was perfectly acceptable, but today, we're much more environmentally conscious. When you convert an old car to electronic fuel injection, like we did on our 1955 Thunderbird, that open fuel vent becomes a source of increased fuel smell as well. High-pressure recirculating fuel systems warm the fuel, returning it to the tank with even more vapor, compounding the problem. In addition, the original vents often do not provide enough air supply for the tank as the fuel level drains. The crew at II Much Fabrication have come up with an innovative solution with their billet Fuel and Differential Vent which allows for sufficient fresh air into the tank, and also incorporates a separator to allow the fuel vapor to return to liquid and drain back into the tank.