The AVS2 carburetors feature annular flow primary boosters with enhanced calibration for improved off-idle and cruising performance. The annular flow booster design delivers improved fuel atomization to eliminate any flat spots that may be persist when the carburetor transitions from idle to throttle. Each annular booster features eight equally spaced holes to improve fuel metering from idle to throttle. The improved flow makes this carburetor ideal for use with a wide variety of small-block and big-block engines with either dual-plane or single-plane intake manifolds.