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.

Notice: Refer to Fastener Notice.

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 to install the valve seals. There is only one size valve seal.





Important: 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 and EN 46119 to compress the valve spring.




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





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


13. Install the spark plugs.