The Edelbrock AVS2 Series Carburetor Calibration Kit #1949 is for tuners looking to improve the performance of their #1912 or #1913 AVS2 Series 800 CFM carburetor.
The Edelbrock AVS2 Series Carburetor Calibration Kit #1940 is for tuners looking to improve the performance of their #1901, #1902, #1903 or #1904 carburetor.