1. Disconnect the battery negative cables from the batteries. Refer to Battery Cable in Engine Electrical.
2. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
3. Remove the upper intake manifold from the lower intake manifold. Refer to Intake Manifold Replacement .
4. Remove the lower intake manifold from the cylinder heads. Refer to Intake Manifold Replacement .
5. Remove the radiator hoses from them engine block.
6. Remove the thermostat housing crossover from the cylinder heads. Refer to Thermostat Housing Crossover Replacement in Engine Cooling.
7. Raise the vehicle and support with safety stands.
8. Remove the exhaust crossover pipe from the exhaust manifolds.
9. Lower the vehicle.
10. Remove the exhaust manifold (s) from the cylinder head (s) from the engine block. Refer to Exhaust Manifold Replacement .



11. Remove the air conditioning compressor and mounting bracket and secure to the side.
12. Remove the vacuum pump if necessary. Refer to Vacuum Pump Replacement .
13. Remove the generator and bracket form the engine assembly. Refer to Generator Replacement in Engine Electrical.



14. Remove the ground strap from the cylinder head.
15. Remove the valve rocker arm, shaft, and push rods from the cylinder head. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .



16. Remove the cylinder head bolts (in sequence) from the cylinder head.



17. Remove the cylinder head from the engine block.
18. Remove the cylinder head gasket from the engine block.
19. Disassemble the cylinder head (if necessary). Refer to Cylinder Head Disassemble .

Important: The engine block surfaces must be clean. Do not use a sealer on the cylinder head gaskets. The cylinder head gaskets are manufactured with the proper amount of sealant "Printed" on its surface. Additional sealer may cause leakage or a malfunction. In addition, some sealers may attack the sealant already on the cylinder head gasket.

Important: The cylinder head gasket material is soft. Handle the cylinder head gasket with care and make sure that the sealing surfaces are not damaged.

1. Assemble the cylinder head (if necessary). Refer to Cylinder Head Assemble .




Important: Connect the rear cylinder head bolt to the cylinder head (left cylinder head only) with a rubber band. Due to the clearances, the bolt must be installed at this time.

2. Apply sealant GM P/N 12346004 or equivalent to the bolt threads and under the bolt heads.
3. Install the cylinder head bolts in the cylinder head.




Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

4. Install the cylinder head bolts and tighten in sequence.

Tighten

1. Tighten the bolts in four passes.
2. Tighten the bolts to 25 N·m (20 lb ft).
3. Tighten the bolts to 75 N·m (55 lb ft).
4. Tighten the bolts to 75 N·m (55 lb ft).
5. In sequence, tighten all bolts an additional 90 to 100 degrees (1/4 + turn).
5. Install the push rods, valve rocker arm, and the shafts to the cylinder head. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
6. Install the thermostat housing crossover to the cylinder heads. Refer to Thermostat Housing Crossover Replacement in Engine Cooling.
7. Install the generator and mounting bracket to the cylinder head. Refer to Generator Replacement in Engine Electrical.
8. Install the vacuum pump if necessary. Refer to Vacuum Pump Replacement .



9. Install the air conditioning compressor and mounting bracket.
10. Install the exhaust manifold (s) to the cylinder head (s). Refer to Exhaust Manifold Replacement .
11. Raise the vehicle.
12. Install the exhaust crossover pipe to the exhaust manifolds.
13. Lower the vehicle.
14. Install the lower intake manifold to the engine block. Refer to Intake Manifold Replacement .
15. Install the upper intake manifold lower intake manifold. Refer to Intake Manifold Replacement .
16. Install the radiator hoses on the engine block.
17. Refill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
18. Connect the battery negative cables to the batteries. Refer to Battery Cable in Engine Electrical.