The Edelbrock 1406 Performer Series 600 CFM electric choke carburetor is a precisely tuned, quality-built carburetor that can handle the rigors of daily driving while delivering consistent, reliable street performance from day to day. Several characteristics make the 1406 Performer Series 600 CFM electric choke carburetor an outstanding street performer. The first one is that metering rods are utilized to transition between circuits. The carburetor is unaffected by engine backfires, which means that there are no power valves to blow out, and the rods can be changed in seconds without carburetor removal or fuel draining. Secondly, the carburetor has the unique ability to hold a tune, so once it is tuned, the carburetor stay’s tuned. What this means to you is that compared to other carburetors, the performance remains consistent and the calibration stays unchanged. The lightweight all-aluminum body features a two-piece body that resists warping and is compatible with gasohol and blended fuels. The simple tub-type bowls and rear-pivot floats all contribute to a carburetor thats reliable, user-friendly and is easily tunable for miles and miles of trouble-free operation. (CALIBRATED FOR FUEL ECONOMY) Designed for small-block and small displacement big-block engines, these carbs are recommended only for stock to Performer level applications. They are not recommended for use on RPM or Torker II intake manifolds. Match with an Edelbrock Performer or Performer EPS manifold or other brands of similar design. Calibrated 2% leaner than #1405. Includes both timed and full vacuum ports for ignition advance. Comes with: Metering Jets - Primary .098, Secondary .095; Metering Rods - .075 x .047; Step-Up Spring - yellow (4 Hg). Use carb Studs #8008 or #8024 if needed.