For 1990-2009 cars only
- Install the hydraulic lash adjusters into their bores in the cylinder head.
- Lubricate the hydraulic lash adjusters with GM P/N 1234550 (Canadian P/N 992704), or equivalent.
- Lubricate the valve tips.
- 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.
- 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.
- Rotate the oil seal in the groove of the number one camshaft journal so the split line (1) is at approximately the 12:00 position before installing the camshaft caps.
- Install the intake camshaft with the notch on the front at approximately the 5 o'clock position (2).
- Install the camshaft caps and hand start the camshaft cap bolts.
- Tighten the camshaft cap bolts in increments of 3 turns until they are seated.
- Apply a 3.5 mm bead of sealer GM P/N 12378521 (Canadian P/N 88901148) to the cylinder head to number 6 camshaft cap mating surface.
- Install the number 6 rear camshaft cap.
- Install the rear cylinder head opening plate and bolts.
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.
Important: The number 1 cylinder must be at top dead center (TDC), crankshaft keyway at the 12 o'clock position.
Notice: Refer to Fastener Notice in the Preface section.
Tighten
Tighten the camshaft caps to 10 N·m (89 lb in).
Tighten
Tighten the number 6 rear camshaft cap to 10 N·m (89 lb in).
Tighten
Tighten the rear cylinder head opening plate bolts to 10 N·m (89 lb in).
