For 1990-2009 cars

### Exhaust Camshaft Installation

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

Note: 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.

3. Position the roller followers on the tip of the valve stem and on the lash adjuster. Apply lubricant GM P/N 12345501 (Canadian P/N 992704) or equivalent.

Note: The engine is timed top-dead center exhaust stroke.

4. When installing the camshafts, ensure the intake camshaft notch is in the 5 o'clock position (2) and the exhaust camshaft notch is in the 7 o'clock position (1). The number 1 piston should be at top dead center (TDC), crankshaft key at 12 o'clock.
5. Set the exhaust 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.

Caution: Refer to Fastener Caution in the Preface section.

7. Tighten the camshaft cap bolts in increments of 3 turns until they are seated, lubricate. Tighten the camshaft caps to 10 N·m (89 lb in).

### Intake Camshaft Installation

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.

Note: 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.

Note: The engine is timed top-dead center exhaust stroke.

5. When installing the camshafts, ensure the intake camshaft notch is in the 5 o'clock position (2) and the exhaust camshaft notch is in the 7 o'clock position (1). The number 1 piston should be at top dead center (TDC), crankshaft key at 12 o'clock.
6. 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.
7. Install the camshaft caps and hand start the camshaft cap bolts.
8. Tighten the camshaft cap bolts in increments of 3 turns until they are seated. Tighten the camshaft caps to 10 N·m (89 lb in).