Designed and calibrated for good street performance and fuel economy, the Edelbrock 1406 electric choke carburetor Features a square flange, 600 cfm, plus timed and full vacuum ports for ignition advance. Two-step metering rods allow independent custom tuning of cruise and power circuits. An easy-to-install linkage adapter kit makes installation on automatic transmission Fords and Chryslers a breeze. And, metering rods are changed without disassembling the carb to further simplify the installation process. A wide selection of rods makes it easier to zero in on optimum calibration for the engine. A mechanical secondary air velocity valve senses airflow according to demand, and automatically regulates a smooth transition from part throttle to wide-open throttle.