The Edelbrock AVS2 Series is the next generation in Edelbrock carburetors. The AVS2 Carburetor is the ideal replacement for the R-1 Avanti, as well as Studebaker 259 and 289 engines. Check out the video below.

The Edelbrock AVS2 Series features annular flow primary boosters with a new calibration for improved off idle and cruising. The annular flow booster design also delivers improved fuel atomization to eliminate flat spots that can be encountered during idle to full throttle transitions.

The typical downleg boosters (on the left), are located in the carburetor primaries and simply provide fuel down the center of the venturi. 

Annular boosters (on the right), feature eight equally spaced smaller holes for better fuel atomization. The improved fuel atomization eliminates flat spots when the carburetor transitions from idle to part throttle for better low rpm performance. The annular boosters can also potentially offer improved mileage in some applications.

Note: If replacing the original AFB carburetor, a new air cleaner base is needed. See part number 1557265B.