Special Tools

J 36660-A Electronic Torque Angle Meter

1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
2. Drain the cooling system. Refer to Cooling System Draining and Filling .
3. Remove the engine cooling fan assembly. Refer to Fan Clutch Replacement .
4. Remove the generator mounting bracket. Refer to Generator Bracket Replacement .



5. Remove the generator mounting bracket stud from the cylinder head.
6. Remove the lower intake manifold. Refer to Lower Intake Manifold Replacement .
7. Remove the exhaust manifold. Refer to Exhaust Manifold Replacement - Right Side .
8. Remove the oil level indicator and tube. Refer to Oil Level Indicator and Tube Replacement .



9. Remove the spark plug wire harness and spark plug wire support.



10. Remove the bolt and the ground strap from the rear of the cylinder head.



11. Remove the bolt and the ground wires from the rear of the cylinder head.
12. Secure the ground strap and the ground wires out of the way.
13. Remove the valve pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .



14. Remove the spark plugs. Refer to Spark Plug Replacement for the 4.3L engine.



15. Remove and discard the cylinder head bolts.




Notice: After removal, place the cylinder head on 2 wood blocks in order to prevent damage to the sealing surfaces.

16. Remove the cylinder head.



17. Remove and discard the cylinder head gasket.



18. Remove the dowel pins (cylinder head locator), if required.
19. Clean the engine block and the cylinder head sealing surfaces.

Notice: Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.

20. Clean the cylinder head bolts and the engine block bolt holes.
21. For further service to the cylinder head refer to the following:

•	Refer to Cylinder Head Disassemble in Engine Mechanical - 4.3L Unit Repair.

•	Refer to Cylinder Head Cleaning and Inspection in Engine Mechanical - 4.3L Unit Repair.

•	Refer to Valve Guide Reaming, and Valve and Seat Grinding in Engine Mechanical - 4.3L Unit Repair.

•	Refer to Cylinder Head Assemble in Engine Mechanical - 4.3L Unit Repair.

1. Clean the cylinder head gasket surfaces on the engine block.
2. Inspect the dowel pins (cylinder head locator) for proper installation.
3. Clean the cylinder head gasket surfaces on the cylinder head.




Important: Do not use any type sealer on the cylinder head gasket (unless specified).

4. Install the NEW cylinder head gasket in position over the dowel pins (cylinder head locator).



5. Install the cylinder head onto the engine block.

Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.




6. Apply sealant GM P/N 12346004 or equivalent to the threads of the NEW cylinder head bolts.
7. Install the cylinder head bolts finger tight.

Notice: Refer to Fastener Notice in the Preface section.




8. Tighten the cylinder head bolts in sequence on the first pass.

Tighten
Tighten the bolts in sequence on the first pass to 30 N·m (22 lb ft).

9. Use the J 36660-A in order to tighten the cylinder head bolts in sequence on the final pass.

Tighten

•	Rotate the long bolts (1, 4, 5, 8, and 9) an additional 75 degrees.

•	Rotate the medium bolts (12 and 13) an additional 65 degrees.

•	Rotate the short bolts (2, 3, 6, 7, 10, and 11) an additional 55 degrees.

10. Install the valve pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
11. Install the lower intake manifold. Refer to Lower Intake Manifold Replacement .



12. Install the spark plug wire harness and the spark plug wire support and bolts.

Tighten
Tighten only the rear spark plug wire support bolt to 12 N·m (106 lb in).

13. Remove the front spark plug wire support bolt.

The front spark plug wire support bolt is used to fasten the oil level indicator tube, and will be installed within the oil level indicator tube installation procedure.

14. Install the spark plugs. Refer to Spark Plug Replacement for the 4.3L engine.
15. Install the oil level indicator tube and indicator. Refer to Oil Level Indicator and Tube Replacement .
16. Install the exhaust manifold. Refer to Exhaust Manifold Replacement - Right Side .



17. Install the bolt and the ground wires to the rear of the cylinder head.

Tighten
Tighten the ground wire bolt to 35 N·m (26 lb ft).




18. Install the bolt and the ground strap to the rear of the cylinder head.

Tighten
Tighten the ground strap bolt to 35 N·m (26 lb ft).




19. Install the stud for the generator mounting bracket.

Tighten
Tighten the generator mounting bracket stud to 20 N·m (15 lb ft).

20. Install the generator mounting bracket. Refer to Generator Bracket Replacement .
21. Install the engine cooling fan assembly. Refer to Fan Clutch Replacement .
22. Fill the cooling system. Refer to Cooling System Draining and Filling .
23. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .