Q: How do you properly replace the intake manifold in V6 engine on Chevrolet El Camino?
A: Make sure the attaching bolts are torque-tightened to the specifications listed for V6. Disconnect the battery ground cable, drain the radiator, and remove the air cleaner. Disconnect the upper radiator hose and heater hose at the manifold, as well as the accelerator linkage at the carburetor, the linkage bracket at the manifold, and the cruise control chain if applicable. Disconnect the booster vacuum pipe at the manifold, the fuel line at the carburetor (plug the line and catch any spillage), the transmission vacuum modulator line if applicable, the idle stop solenoid if applicable, the distributor wires (mark each wire with pieces of tape for ease of reassembly), the temperature sending unit wire, and vacuum hoses from the distributor, TVS, and EFE valve pipe at the carburetor (mark hoses with pieces of tape for ease of reassembly), along with the coolant by-pass hose at the manifold. Remove the distributor cap, mark the rotor position, and remove the rotor to access the left intake manifold special six-lobed socket head bolt. Remove the six-lobed socket bolt with GM tool J-24394 or equivalent, then remove the accelerator linkage springs and compressor top bracket if applicable, followed by the remaining intake manifold bolts (there are 10). Lift the intake manifold, complete with carburetor, from the engine without prying on the mating edges to avoid damage. If replacing the intake manifold with a new one, transfer the carburetor and carburetor attaching bolts, temperature or oil sending unit, water outlet and thermostat (using a new gasket), EGR valve (using a new gasket), heater hose, and water pump hose adapter fittings, as well as the carburetor choke assembly. Before installing the manifold, cover the engine cavity with lint-free rags and clean the engine block cylinder heads and manifold gasket surfaces, ensuring all old gasket material and sealing compound are removed. Place the new intake manifold gasket and rubber manifold seal in position at the front and rear rails of the cylinder block, ensuring the pointed end of the seal fits snugly against the block and head, and apply RTV or equivalent sealant to the ends of the seals before installing. Install the one-piece manifold gasket and carefully set the manifold in place, locating it on the engine block dowel pins. Install the manifold-to-cylinder head attaching bolts, starting with the number 1 and number 2 bolts, gradually tightening these two until snug, then install the rest of the bolts in sequence and tighten them to the torque specifications. Connect or re-install the components in the reverse order of removal, reconnect the battery cable, close the drain plug, and refill the cooling system. Start the engine and check for leaks, adjusting the ignition timing and carburetor idle as necessary.