Edelbrock Carburetor Thunder Series 4-Barrel 800 CFM Electric Choke Calibration Satin FinishEdelbrock's Annular Flow Booster technology brings superior fuel atomization to all high horsepower small and big block engines with the AVS2 800 CFM Electric Choke Carburetor #1913 that is specially calibrated to make power. Annular Flow Boosters deliver near EFI like drivability that you can feel as soon as you step on the gas. Fuel distribution is refined by eight equally spaced orifices in the booster rings that replace down leg boosters which