Tools Required

Caution: Wear safety glasses in order to avoid eye damage.

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.

Important: 

•	Do not use the cylinder head bolts again. Install NEW cylinder head bolts during assembly.

•	Do not use any type sealant on the cylinder head gasket, unless specified.

•	The cylinder head gaskets must be installed in the proper direction and position.

1. Clean the engine block cylinder head bolt holes, if required.

Thread repair tool J 42385-107 may be used to clean the threads of old threadlocking material.

2. Spray cleaner GM P/N 12346139 (Canadian P/N 10953463), GM P/N 12377981 (Canadian P/N 10953463) or equivalent into the hole.
3. Clean the cylinder head bolt holes with compressed air.
4. Check the cylinder head locating pins for proper installation.




Important: When properly installed, the tab on the left cylinder head gasket will be located left of center or closer to the front of the engine.

5. Install the NEW left cylinder head gasket onto the locating pins.



6. Install the cylinder head onto the locating pins and the gasket.
7. Install the NEW cylinder head bolts.

Notice: Refer to Fastener Notice in the Preface section.




8. Tighten the cylinder head bolts.

Tighten

1. Tighten the M11 cylinder head bolts a first pass in sequence to 30 N·m (22 lb ft).
2. Tighten the M11 cylinder head bolts a second pass in sequence to 90  degrees using the J 36660-A .
3. Tighten the M11 cylinder head bolts (1,2,3,4,5,6,7,8) to 90 degrees and the M11 cylinder head bolts (9 and 10) to 50 degrees a final pass in sequence to using the J 36660-A .
4. Tighten the M8 cylinder head bolts (11,12,13,14,15) to 30 N·m (22 lb ft). Begin with the center bolt (11) and alternating side-to-side, work outward tightening all of the bolts.



9. The cylinder head gasket displacement can be verified by markings visible on the top side of the left gasket locating tab.

Some 5.3L head gaskets may have 48 or 53 stamped onto the locating tab.