Holley 0-90470 Truck Avenger 470 CFM Vacuum Secondary Electric Choke Carburetor Adjustable vacuum secondary to tune for fuel economy or acceleration Electric choke, easy to adjust and designed to prevent accidental over-adjustment Square fuel bowls with side hung floats for precise fuel control Clear sight plugs to initially set fuel level without the risk of spilling fuel Externally adjustable spring-loaded needle and seats promote stable fuel levels for improved fuel control