The Edelbrock # 1905 AVS2 650 cfm carburetor is the next generation of Edelbrock carburettors. Developed and calibrated for optimal road performance in small block and some big block engines. The AVS2 has ring-shaped primary amplifiers with a new calibration for improved idle and travel performance. The annular flow amplifier design provides improved fuel atomization to eliminate flat spots that can occur when the carburetor changes from idle to full throttle. Each annular flow booster has eight equally spaced openings to improve fuel metering from idle to the main circuit. The improved flow measurement makes this carburettor ideal for use with a large number of small and large block engines with double or single-surface intake manifolds. The Edelbrock # 1905 AVS2 has both a time-controlled and a full vacuum connection for the ignition timing. It is supplied with: dosing nozzles - primary .101, secondary .098; Dipsticks - .070 x .037; Step-Up Spring - orange (5 "Hg).