Tools Required

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: 

•	Do not use the cylinder head bolts again. Install NEW cylinder head bolts during assembly.

•	Do not use any type sealant on the cylinder head gasket, unless specified.

•	The cylinder head gaskets must be installed in the proper direction and position.

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




Important: When properly installed, the tab on the left cylinder head gasket is located left of center, or closer to the front of the engine, and the words "This Side Up", and the engine displacement, is visible.

7. Inspect the gasket for proper installation.



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

10. Tighten the first design cylinder head bolts.

Tighten

1. Tighten the first design M11 cylinder head bolts (1-10) a first pass in sequence to 30 N·m (22 lb ft).
2. Tighten the first design M11 cylinder head bolts (1-10) a second pass in sequence to 90 degrees using the J 45059 .
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 using the J 45059 .
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 J 45059 .
3. Tighten the second design M11 cylinder head bolts (1-10) a final pass in sequence to 70 degrees using the J 45059 .
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.