Tools Required

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




Important: The cylinder head bolts are NOT reusable.

5. 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.

6. Remove the cylinder head.



7. Remove the cylinder head gasket.
8. Discard the gasket.
9. Discard the cylinder head bolts.
10. Clean and inspect the cylinder head. Refer to Cylinder Head Cleaning and Inspection .

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 may be used to clean the threads of old threadlocking material.

2. Spray cleaner GM P/N 12346139 (Canadian P/N 10953463), GM P/N 12377981 (Canadian P/N 10953463) or equivalent into the hole.
3. Clean the cylinder head bolt holes with compressed air.




Important: First design engine blocks have different drill and tap depths using both medium length 100 mm (3.94 in) and long 155 mm (6.1 in) M11 cylinder head bolts. Second design engine blocks use only the medium length 100 mm (3.94 in) bolt with a common drill and tap depth.

4. Measure the depth of the cylinder head bolt holes (1-10) and select the correct length bolts as required.
5. Check the cylinder head locating pins for proper installation.



6. Inspect the displacement markings (1) on the gasket, for proper usage.




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.

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



8. Install the cylinder head onto the locating pins and the gasket.
9. Install the NEW cylinder head bolts.

Notice: Refer to Fastener Notice in the Preface section.




10. Tighten the first design cylinder head bolts.

Tighten

1. Tighten the first design M11 cylinder head bolts a first pass in sequence to 30 N·m (22 lb ft).
2. Tighten the first design M11 cylinder head bolts a second pass in sequence to 90  degrees using the .
3. Tighten the first design 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 to using the .
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.
11. Tighten the second design engine block cylinder head bolts.

Tighten

1. Tighten the second design M11 cylinder head bolts (1-10) a first pass in sequence to 30 N·m (22 lb ft).
2. Tighten the second design M11 cylinder head bolts (1-10) a second pass in sequence to 90  degrees using the .
3. Tighten the second design M11 cylinder head bolts (1-10) a final pass in sequence to 50 degrees using the .
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.
12. Install the pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
13. Install the left exhaust manifold. Refer to Exhaust Manifold Replacement - Left Side in Engine Exhaust.
14. Install the coolant air bleed pipe. Refer to Coolant Air Bleed Pipe Assembly Replacement in Engine Cooling.
15. Install the generator mounting bracket. Refer to Generator Replacement in Engine Electrical.