Tools Required

1. Remove the generator bracket. Refer to Generator Replacement in Engine Electrical.
2. Remove the intake manifold. Refer to Intake Manifold Replacement .
3. Remove the coolant air bleed pipe. Refer to Coolant Air Bleed Pipe Assembly Replacement in Engine Cooling.
4. Remove the left exhaust manifold. Refer to Exhaust Manifold Replacement - Left Side in Engine Exhaust.
5. Remove the pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .




Important: The cylinder head bolts are NOT reusable.

6. Remove the cylinder head bolts.

Notice: After removal, place the cylinder head on 2 wood blocks in order to prevent damage to the sealing surfaces.

7. Remove the cylinder head.



8. Remove the cylinder head gasket.
9. Discard the gasket.
10. Discard the cylinder head bolts.
11. Clean and inspect the cylinder head. Refer to Cylinder Head Cleaning and Inspection in Engine Mechanical - 4.8L, 5.3L, and 6.0L Unit Repair.

Caution: Wear safety glasses in order to avoid eye damage.

Notice: Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.

Important: 

1. Clean the engine block cylinder head bolt holes (if required).

Thread repair tool J 42385-107, found inJ 42385-200 may be used to clean the threads of old threadlocking material.

2. Use spray cleaner GM U.S. P/N 12346139, P/N 12377981, Canada P/N 10953463, or equivalent into the hole.
3. Clean the cylinder head bolt holes with compressed air.
4. Check the cylinder head locating pins for proper installation.

Important: When properly installed, the tab on the left cylinder head gasket will be located left of center or closer to the front of the engine.




5. Install the NEW left cylinder head gasket onto the locating pins.



6. Install the cylinder head onto the locating pins and gasket.
7. Install the NEW cylinder head bolts.




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.

8. Tighten the cylinder head bolts.

Tighten

1. Tighten the M11 cylinder head bolts a first pass in sequence to 30 N·m (22 lb ft).
2. Tighten the M11 cylinder head bolts a second pass in sequence to 90 degrees using J 36660-A .
3. Tighten the M11 cylinder head bolts (1,2,3,4,5,6,7,8) to 90 degrees and the M11 cylinder head bolts (9 and 10) to 50 degrees a final pass in sequence using J 36660-A .
4. Tighten the M8 cylinder head bolts (11,12,13,14,15) to 30 N·m (22 lb ft). Begin with the center bolt (11) and alternating side-to-side, work outward tightening all of the bolts.



9. The cylinder head gasket displacement can be verified by markings visible on the top side of the left gasket locating tab.

•	Some 4.8/5.3 L head gaskets may have 53 stamped onto the locating tab.

•	Some 6.0 L head gaskets may have 60 stamped onto the locating tab.

10. Install the pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
11. Install the left exhaust manifold. Refer to Exhaust Manifold Replacement - Left Side in Engine Exhaust.
12. Install the coolant air bleed pipe. Refer to Coolant Air Bleed Pipe Assembly Replacement in Engine Cooling.
13. Install the intake manifold. Refer to Intake Manifold Replacement .
14. Install the generator bracket. Refer to Generator Replacement in Engine Electrical.