Streamlined Rochester Quadrajet Carburetor for Chevy and GMC Trucks 1966-1973

This Quadrajet carburetor is a versatile and easy-to-service 4-barrel, two-stage, down-draft design that can be adapted to a wide range of engine sizes without major modifications. It is available in three basic models - 4M (manual choke), 4MV (automatic choke with manifold-mounted thermostat), and 4MC (automatic choke with side-mounted choke housing and coil).

The carburetor's unique centrally located fuel bowl ensures an adequate fuel supply to all bores, resulting in excellent performance even during severe vehicle maneuvers. The float system features a solid, lightweight plastic float pontoon that allows the use of a single float to maintain a constant fuel level. Two types of float needle valves are used - a diaphragm-assisted version for smaller floats and high-pressure fuel pumps, and a standard needle and brass seat design.

The idle system, located on the primary (fuel inlet) side of the carburetor, supplies the correct air-fuel mixture during idle and off-idle operation when airflow through the venturi is not sufficient for efficient main discharge nozzle metering. It consists of idle tubes, passages, air bleeds, channel restrictions, and adjustable mixture needles.

This Quadrajet carburetor is a direct replacement for the 1901-GG Rochester Quadrajet 4MV used on 1966-1973 and 1975-1979 Corvettes, as well as 1968-1973 Chevrolet and GMC trucks (Part No. 1901R). It is also interchangeable with a wide range of Chevrolet part numbers, including 7026202, 7026203, 7026210, 7027202, 7027203, 7027212, 7027213, 7040007, 7040021, 7046904, 7047207, 7047303, 7047305, 7047306, 7047307, 7047316, 7047319, 17054236, 17054709, and 170549.

Fitment-wise, this carburetor features a vacuum secondary, manual choke, and spread-bore design, making it well-suited for daily driving applications. It is compatible with 327-454 ci V8 engines found in 1966-1973 Chevrolet, Chevrolet, GMC, and Cadillac vehicles.

While this universal performance carburetor is designed to improve throttle response and overall performance, some vehicles may experience overly rich running conditions resulting in black smoke from the exhaust. In such cases, the included tool and copper pin can be used to block the air channels and correct the fuel mixture.

The carburetor's specifications include a 750 CFM rating, 185mm main jets, 120mm idle jets, 7.3mm auxiliary venturi, 28mm venturi (choke tube), 110mm air correction jets, and a 3.3mm needle valve.

Please note that this product does not include installation instructions, so it is recommended to refer to relevant online resources and follow the proper steps carefully. If you have any questions or concerns, feel free to contact our customer service before making a purchase.

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