The amount of fuel sent to each nozzle is determined by a vacuum control signal generated by "a highly efficient annular venturi between the air-meter body and a diffuser cone" in the air-meter assembly (Corvette Shop Manual, pgs. 6M-34). Ken designed and fabricated a new line using 1/4-inch steel tubing. On the air-meter end, a 1/4-inch "O" ring is used to seal the line, and a 1/4-inch compression nut and 90-degree fitting are used at the fuel meter end. If this vacuum line has the smallest leak, the main fuel-control diaphragm will not function properly and drivability will be erratic. Another 1/2-inch line runs between fuel-meter main diaphragm housing and the air-meter adapter to vent gas fumes. This piece was fabricated from 1/2-inch aluminum tubing and connected to the original tubing.