The 5.7-liter GM engine, or the well-known 350-cubic inch engine, is part of the family of small blocks that sprung from the basic design of the 265-cubic inch engine from 1955. The 350, which shares the same block as the 327-cubic inch engine, according to Auto Zone, is one of the most common V-8 engines that GM produces. Parts are interchangeable with several other GM V-8 engines and are easily obtained, even for the older engines.
Jack up the vehicle with the floor jack and support it with jack stands if your 5.7-liter engine is a 1973 or older. Slide the drain pan under the oil pan and loosen the oil drain bolt. Allow the oil to drain. Remove the oil pan, using the appropriate sockets.
Slide the second drain pan under the radiator petcock on all year 5.7-liter engines. Open the petcock to allow the coolant to drain. Remove the radiator cap so the coolant will drain faster.
Break loose the fan pulley bolts, but do not remove them. Loosen the adjusting bolts for the accessories. Depending on your year engine, you may have an air compressor and an air pump, in addition to the alternator and power steering pump. Push the accessory toward the engine to loosen tension on the belts. Lift the belts off the pulleys.
Remove the power steering pump, but do not remove the hoses. Set it out of the way. Remove the air pump. If any of the brackets overlap the timing cover, remove the brackets with the appropriate sockets.
Unbolt and remove the water pump. Remove the crankshaft pulley using the appropriate socket, then install the harmonic balancer puller on the balancer. Hold the crankshaft with a prybar or a flywheel turner to keep it from turning. Turn the center screw on the puller lockwise to remove the balancer.
Remove the timing cover, using the appropriate socket. Clean the gasket-mating surfaces of the water pump, timing cover and block using shop rags and a scraper. If you removed the oil pan, clean the gasket-mating surface of the oil pan and the block.
Pry the oil seal out of the cover with a screwdriver or seal removal tool. Install a new seal with the lip inside the cover. Press the seal into place using a large socket. Coat the seal with engine oil.
Apply a 1/8-inch bead of RTV silicone to the oil pan front lip and the joint that is formed by the oil pan and block. Smear a thin layer of RTV silicone on the oil pan. Position the oil pan gasket onto the oil pan. Allow the bead of silicone to skin up. When you touch it, it should not stick to your finger.
Install the timing cover on the block, but do not tighten the bolts -- just screw them in a couple threads. Apply a 1/8-inch thick bead of RTV silicone on the bottom of the timing cover seal, then install it on the cover. Tighten the bolts evenly while aligning the cover over the dowel pins.
Reinstall the oil pan. Reinstall the water pump, harmonic balancer, crankshaft pulley, accessories and belts. Tighten the belts until they can be twisted 90 degrees between the pulleys. Fill the engine with oil. Refer to the owner's manual for the type and amount.
Tighten the radiator petcock. Fill the radiator. Refer to the owner's manual for the percentage of antifreeze. Start the engine and check for leaks while allowing it to come to operating temperature. Top off the coolant as needed. Reinstall the radiator cap.
