For 1990-2009 cars

1. Install the hydraulic lash adjusters into their bores in the cylinder head.
2. Lubricate the hydraulic lash adjusters with GM P/N 12345501 (Canadian P/N 992704) or equivalent.
3. Lubricate the valve tips.

Important: Used roller followers must be returned to the original position on the camshaft. If the camshaft is being replaced, the roller followers actuated by the camshaft must also be replaced.

4. Position the roller followers on the tip of the valve stem and on the lash adjuster. Lubricate roller followers with GM P/N 12345501 (Canadian P/N 992704) or equivalent.
5. Set the intake camshaft on top of the roller followers in the camshaft bearing journals. Lubricate with GM P/N 12345501 (Canadian P/N 992704) or equivalent.
6. Install the camshaft caps and hand start the camshaft cap bolts.
7. The timing chain sprocket alignment notch should be oriented to the 11 o'clock position.

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.

8. Tighten the camshaft cap bolts in increments of 3 turns until they are seated.

Tighten
Tighten the camshaft caps to 10 N·m (89 lb in).

9. Apply sealer GM P/N 12378521 (Canadian P/N 88901148) or equivalent to rear intake camshaft cap.
10. Install the rear intake camshaft cap bolts.

Tighten
Tighten the bolts to 25 N·m (18 lb ft).