Installation Procedure

WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Assemble the cylinder head, if necessary. Refer to Cylinder Head Assemble .
Install the cylinder head locator pins, if necessary.

Fig 1: Cylinder Head Locator Pins
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Do not use any type of sealer on the cylinder head gasket.
Install a NEW cylinder head gasket.

Fig 2: Cylinder Head Gasket
Courtesy of GENERAL MOTORS CORP.
Install the cylinder head.

Fig 3: Cylinder Head
Courtesy of GENERAL MOTORS CORP.
Apply sealant GM P/N 12346004, (Canadian P/N 109534480), or equivalent to the threads of the cylinder head bolts.
NOTE: Refer to FASTENER NOTICE .
Install the cylinder head bolts until snug.

Fig 4: Cylinder Head Bolts
Courtesy of GENERAL MOTORS CORP.
Tighten the cylinder head bolts using the sequence shown.
Tighten
1. 7.1. Tighten the bolts a first pass to 30 N.m (22 lb ft).
2. 7.2. Tighten the long bolts (1, 4, 5, 8, 9) a final pass to 75 degrees using the J 36660-A.
3. 7.3. Tighten the medium bolts (12,13) a final pass to 65 degrees using the J 36660-A.
4. 7.4. Tighten the short bolts (2, 3, 6, 7, 10, 11) a final pass to 55 degrees using the J 36660-A.
Fig 5: Tightening Sequence For Cylinder Head Bolts
Courtesy of GENERAL MOTORS CORP.
Install the spark plug wire support and bolts.
Tighten

Tighten the bolts to 12 N.m (106 lb in).

Fig 6: Spark Plug Wire Support & Bolts
Courtesy of GENERAL MOTORS CORP.
Install the spark plugs.
If installing NEW spark plugs measure for the correct gap. Adjust the spark plug gap if necessary.
Specification

Spark plug gap to 1.52 mm (0.060 in).

Tighten
- Tighten the plugs in a USED cylinder head to 15 N.m (11 lb ft).
- Tighten the plugs on the initial installation of a NEW cylinder head to 30 N.m (22 lb ft).
Fig 7: Spark Plug
Courtesy of GENERAL MOTORS CORP.
Install the ECT sensor. If reusing the old sensor, apply sealant GM P/N 12346004 (Canadian P/N 109534480), or equivalent to the threads.
Tighten

Tighten the sensor to 20 N.m (15 lb ft).

Fig 8: ECT Sensor
Courtesy of GENERAL MOTORS CORP.
Position the ground strap (5) and harness ground (4).
Install the harness ground bolt.
Tighten

Tighten the bolt to 16 N.m (12 lb ft).

Fig 9: Ground Strap & Harness Ground
Courtesy of GENERAL MOTORS CORP.
Install the P/S pump bracket stud.
Tighten

Tighten the stud to 20 N.m (15 lb ft).

Fig 10: Power Steering Pump Bracket Stud
Courtesy of GENERAL MOTORS CORP.
Slide the P/S pump bracket rearward.
Install the bolts and nuts for the P/S pump bracket.
Install the P/S pump rear bracket front nut.
Tighten the P/S pump rear bracket nut.
Tighten

Tighten the bolts and nuts to 41 N.m (30 lb ft).

Fig 11: Power Steering Bracket, Nuts & Bolts
Courtesy of GENERAL MOTORS CORP.
Position the bracket and wiring harness.
Install the junction block bracket bolt.
Tighten

Tighten the bolt to 25 N.m (18 lb ft).
Install the left side pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
Install the left exhaust manifold. Refer to EXHAUST MANIFOLD REPLACEMENT - LEFT (4.3L ENGINE) .
Install the lower intake manifold. Refer to Intake Manifold Replacement - Lower .
Install the drive belt. Refer to Drive Belt Replacement .

Fig 12: Junction Block Bracket Bolt & Wiring Harness
Courtesy of GENERAL MOTORS CORP.
Fill the cooling system. Refer to DRAINING AND FILLING COOLING SYSTEM .