I have a vacuum leak that causes a whistle when I'm not depressing the gas pedal. My suspicion is that the culprit is this deteriorated rubber vacuum tube elbow. I have been to all of the auto parts stores and no one has them. Has anyone found a source for these? The elbow I'm after is on the driver's side of the intake manifold closest to the front of the engine. (It is shiny because I tried putting vaseline on it.) Thanks for your help!