The Edelbrock AVS2 Series #1906 is a satin-finished four-barrel carburetor with electric choke that is designed and calibrated for optimum street performance in engines that require an air-fuel flow of 650 CFM. The AVS2 is a perfect replacement or upgrade that features annular flow primary boosters with a new calibration for improved off-idle and cruising performance. The annular flow booster design delivers improved fuel atomization to eliminate flat spots that may be encountered as the carburetor transitions from idle to full throttle. Each annular flow booster features eight equally spaced orifices to improve fuel metering from idle to the main circuit. The improved flow metering makes this carburetor ideal for use with a wide variety of small and big-block engines with either dual or single-plane intake manifolds. Features both timed and full vacuum ports for ignition advance. It comes with: .101 primary and.098 secondary metering jets; .070 x .037 metering rods; orange (5" Hg) step-up spring.