How to Install a Holley Carburetor in a Chevy 350by John Stevens J.D.
Holley carburetors are among the most widely used and recognizable high-performance carburetors on the market. The Chevy 350's stock Rochester was design to provide smooth operation for day-to-day driving rather than for the high-performance applications Holley carburetors are designed for. Replacing the stock carburetor with a Holley unit is relatively simple, and the increase in performance can be dramatic.
Remove the air cleaner assembly from the top of the stock carburetor. Chevrolet air cleaner assemblies attach to the top of the carburetor with a single wing nut, which installs onto a stud located at the top of the carburetor. The wing nut is located in the center of the top of the air cleaner assembly. Remove the wingnut, then lift the air cleaner assembly off of the carburetor.
Disconnect the throttle linkage and vacuum lines from the carburetor. The throttle linkage is on the driver's side of the carburetor and attaches to the carburetor with a single clip. Pull the clip off of the linkage arm with a pair of pliers, then slide the linkage away from the carburetor to disconnect it. At least one rubber vacuum line is attached to the base of the carburetor. Some models have more than one vacuum line depending on which accessories the engine is equipped with. Pull each vacuum line off of the carburetor.
Disconnect the fuel line from the carburetor. The fuel line attaches to the front of the stock carburetor with a single nut. Loosen the nut with a wrench, then pull the fuel line away from the carburetor to disconnect it.
Remove each of the four nuts which attach the carburetor to the top of the engine with a wrench, then lift the carburetor off of the engine. A single nut is located at each corner of the bottom of the carburetor. Lift the carburetor gasket away from the top of the engine after the carburetor is removed.
Place a new carburetor gasket onto the top of the engine, then lower the Holley carburetor onto the gasket. Install and tighten each of the carburetor's four retaining nuts with a wrench. Slide the tip of the fuel line into the fuel fitting on the front of the Holley, then tighten the nut on the end of the fuel line with a wrench.
Insert the end of the throttle linkage into the driver's side of the carburetor, then place the clip over the linkage to secure it in place. The base of the Holley features several metal nipples. Plug any vacuum lines used by the engine into these nipples. Plug any unused nipple with a plastic cap, commonly available at automotive parts stores.
Remove the stud in the center of the old carburetor with a wrench, then insert and tighten the stud into the top of the Holley. Slide the air cleaner assembly onto the stud on the Holley, then tighten the wing nut onto the top of the air cleaner assembly to secure the assembly in place and to complete the installation.