Disconnect the cable from the negative battery terminal. On carbureted and TBI models, remove the air cleaner assembly, while on TPI models, remove the air intake duct. Remove the distributor cap to prevent damage when the engine is raised. Unbolt and remove the top half of the fan shroud, then raise the vehicle and support it on jack-stands. Drain the engine oil and disconnect the exhaust crossover pipe at the exhaust manifold flanges, lowering the exhaust pipes and suspending them from the frame with wire. If equipped with an automatic transmission, remove the converter shroud; if equipped with a manual transmission, remove the flywheel cover. Remove the starter, then turn the bolt at the center of the vibration damper to rotate the crankshaft until the timing mark is facing down at the 6 o'clock position, moving the forward crankshaft throw to the top for clearance at the front of the oil pan. Remove the throughbolt at each engine mount, then raise the engine slightly to allow the oil pan to clear the crossmember, preferably using an engine hoist with lifting chains. Alternatively, place a floor jack and a block of wood under the oil pan, ensuring the wood block spreads the load to prevent damage. Raise the engine slowly until wood blocks can be placed between the frame front crossmember and the engine block, checking clearances around the engine, especially at the distributor and cooling fan. Lower the engine onto the wood blocks, ensuring it is firmly supported, and if a hoist is used, keep the lifting chains secured. Remove the oil pan bolts, noting the different sizes and their locations, then remove the oil pan. Before reinstalling, ensure the sealing surfaces on the pan, block, and front cover are clean, removing any old gasket material if the original oil pan is being reused. Always use new gaskets and seals when installing the pan, lifting it into position and installing all bolts finger tight, tightening the end bolts first and then the remaining bolts from the center out to the ends. Lower the engine onto the mounts and install the throughbolts, then follow the removal steps in reverse order, filling the crankcase with the correct grade and quantity of oil, starting the engine, and checking for leaks.
Posted by GMPartsGiant Specialist