Drain the cooling system and remove the PCV and canister purge hoses. Disconnect the accelerator cable, speed control linkage, and automatic transmission cable, then remove the accelerator cable bracket. Label and disconnect all vacuum lines connected to the intake manifold, and remove the distributor. Relieve the fuel system pressure and disconnect the fuel supply and return lines. Disconnect the radiator, heater, and water pump bypass hoses from the water outlet, as well as the throttle body cooler hoses, noting that the heater outlet and coolant bypass tubes are pressed in and cannot be removed. Disconnect the electrical connectors from the coolant temperature sending unit, air charge temperature sensor, throttle position, idle speed control solenoid, EGR sensors, fuel injectors, and fuel charging assembly. Remove the air intake plenum, then loosen the lower intake manifold bolts and nuts in 1/4-turn increments until they can be removed by hand. The manifold may be stuck to the cylinder heads, requiring force to break the gasket seal; use a prybar carefully to avoid damaging the gasket sealing surfaces. Ensure the mating surfaces of the cylinder heads, block, and manifold are perfectly clean during installation, using gasket removal solvents as needed. The manufacturer recommends using guide pins made from extra manifold bolts for easier installation. If the manifold was disassembled, reassemble it, applying electrically conductive sealant on the temperature sending unit threads and using a new EGR valve gasket. Remove all traces of sealant and old gasket material with a gasket scraper, then clean the mating surfaces with lacquer thinner or acetone, covering the lifter valley with shop rags to keep debris out of the engine. Chase the threads in the bolt holes with a tap of the correct size and use compressed air to remove debris. Apply a 1/8-inch wide bead of RTV sealant to the four corners where the manifold, block, and heads converge, ensuring to install and tighten the manifold promptly to prevent leaks. Apply contact adhesive to the manifold gasket mating surface on each cylinder head, position the gaskets, and ensure they are aligned correctly. Position the end seals on the block and apply RTV sealant where they meet the heads. Carefully set the manifold in place while the sealant is still wet, avoiding disturbance of the gaskets, and install the bolts, tightening them to the specified torque. The remaining installation steps are the reverse of removal, followed by changing the engine oil and refilling the cooling system. Start the engine and check for oil and coolant leaks at the intake manifold joints, then recheck the mounting bolt torque.