Cylinder Head Assemble

Cylinder Head Assemble

Special Tools
* EN 46119 - Valve Spring Compressor Adapter
* J 8062 - Valve Spring Compressor
* J 38820 - Valve Stem Seal Remover/Installer




1. Apply sealant GM P/N 12378521 (Canadian P/N 88901148) or equivalent to the threads.

Caution: Refer to Fastener Caution (Fastener Caution).

2. Install the (end) oil gallery plugs. Tighten the oil gallery plugs to 38 Nm (28 ft. lbs.).




3. Apply sealant GM P/N 12378521 (Canadian P/N 88901148) or equivalent to the plugs.
4. Install the inner oil gallery plugs.




5. Apply sealant GM P/N 12378521 (Canadian P/N 88901148) or equivalent to the plug.
6. Install the water jacket plug.




7. Use J 38820 - installer to install the valve seals. There is only one size valve seal.





Note: Lubricate the valve stems with clean engine oil before installing.

8. Install the valves. 0.075 mm (0.003 in) oversized valves are available if the valve guides needed to be reamed. Use the same, original size valve seal.




9. Install the valve spring and the valve spring retainer.




10. Use J 8062 - compressor and EN 46119 - adapter to compress the valve spring.




11. Install the valve keys.
12. Remove J 8062 - compressor and EN 46119 - adapter.





Note: Do not try to centralize the electrode on the spark plug. The electrode is offset by design.

13. Install the spark plugs.