Removing an Intake Manifold

Removing the intake manifold from any classic car requires careful preparation to prevent damage and ensure a smooth reinstallation. We join Mark Simpson in the shop as he takes on the task of replacing his Barry Grant six-shooter intake in his 1935 Chevrolet.

Simpson explains it’s a good idea to begin by disconnecting the negative battery cable to eliminate the possibility of accidental electrical shorts. Drain the cooling system to a level below the intake manifold, as coolant passages are incorporated into the manifold and coolant will spill into the engine valley if not drained first. Remove the air cleaners and disconnect the throttle linkage, transmission TV cable for the 700R4 transmission, choke connections, fuel lines, vacuum hoses, and any electrical connections attached to the carburetors or intake manifold. Labeling all connections will simplify reassembly.

Next, disconnect the distributor cap and mark the distributor position relative to the intake manifold and engine block. Removing the distributor entirely is recommended because the distributor shaft engages the intake manifold opening and can interfere with manifold removal.

Remove the upper radiator hose, heater hoses, and any brackets attached to the intake manifold. Carefully loosen and remove the intake manifold bolts following a crisscross pattern to relieve stress evenly across the casting. Once all bolts are removed, gently break the gasket seal using a soft pry tool or plastic wedge. Avoid excessive force that could damage the cylinder head sealing surfaces.

With assistance if necessary, lift the intake manifold straight upward and away from the engine. The manifold is heavier than a typical single-carburetor intake due to its size and design. Take care not to drop debris into the exposed intake ports or lifter valley. Immediately cover all openings with clean shop towels or protective covers.
Inspect the intake manifold, cylinder head surfaces, and gasket areas for signs of vacuum leaks, coolant seepage, or gasket deterioration. Thoroughly clean all mating surfaces without gouging the aluminum. Before reinstallation, verify that the correct intake gaskets, end seals, sealant, and torque specifications are available to ensure a leak-free installation and reliable engine performance.