Tools Required

Notice: In order to avoid damage, install the spark plugs after the cylinder head has been installed on the engine.

1. Install NEW cylinder head plugs. Coat the plugs with sealer GM P/N 12378521 (Canadian P/N 88901148) or equivalent.



2. Inspect the valve springs. Refer to Engine Mechanical Specifications for the tolerances.
3. Look for the following conditions when inspecting the valve springs:

•	Expanded height

•	Unparallel spring ends

•	Spring tension using J 9666

•	Any distorted springs should be replaced




4. Assemble the valves.
5. Use the following steps to measure valve runout:

5.1.	Apply a dab of Prussian blue on the entire valve face. Seat the valve but do not rotate it. The Prussian blue traces transferred to the valve seat are an indication of concentricity of the valve seat.

5.2.	Clean all traces of Prussian blue.

5.3.	Apply a dab of Prussian blue on the valve seat and repeat the check. The traces of Prussian blue transferred to the valve face indicates valve face concentricity.




6. Replace the valves, if required.



7. Install the new valve seals. Fully seat the seals on the valve guides.



8. Install the spring.



9. Install the retainer.
10. Using the J 8062 and the J 43963 , compress the valve spring.
11. Install the valve keys.
12. Slowly release the J 8062 and the J 43963 from the valve/spring assembly.
13. Inspect for proper valve key seating.



14. Measure the valve installed height using a ruler. Measure from the base of the valve spring to the top of the valve. Refer to Engine Mechanical Specifications for the correct specification.
15. Install the remaining valves, springs, and other components.

Notice: Refer to Fastener Notice in the Preface section.




16. Install the cylinder head air bleed tube.

Tighten
Tighten the tube to 15 N·m (11 lb ft).