Here’s what I fabricated. I had a 5/16 ball bearing and set it up so the vacuum could pull it up then drop down maybe 1/16 to 1/8 inch. It definitely lets gas drip through. I cut a couple notches on the sides so the gas could drip when the ball bearing is down. I also put a 6-32 threaded set screw so it doesn’t vibrate off. It seems like such a fire hazard though. I haven’t run the car, just turned it over in the garage. I figure I can put a long pipe in between so I can adjust to not drop gas on the headers. Before I run this I wonder if anyone ever started a fire from this. Seems dangerous.