Edelbrock AVS2 500 CFM Carburetor w/Manual Choke Satin Finish (Non-EGR)THE ULTIMATE PERFORMANCE CARBURETOR Designed and calibrated for small cubic inch engines and dual quad applications such as our RPM Dual Quad Air Gap, Edelbrock C 26, F 28 and Street Tunnel Ram. For single carb applications, match with an Edelbrock Performer or Performer EPS manifold or other brands of similar design. Includes both timed and full vacuum ports for ignition advance. #1901 #1902 are calibrated for single quad applications and factory