REVISED CYLINDER HEAD GASKET IMPROVED SEALING

MODELS: 1987-89 C/K, R/V, S/T, M, G AND P LIGHT TRUCKS WITH 4.3L, 5.0L, AND 5.7L ENGINES (VIN CODES H, K AND Z) AND C5, C6 MEDIUM TRUCKS WITH 5.7L (VIN CODE A) ENGINE.

THIS BULLETIN CANCELS AND REPLACES GMC TRUCK SERVICE BULLETIN 89-T-16 TO ADD THE 1987-89 S/T AND M MODELS, AND 4.3L ENGINE APPLICATION AND PART NUMBER.

A cylinder head gasket with improved sealing characteristics is now available for service use on all 4.3L, 5.0L and 5.7L engine applications. The ap- plicable part numbers are listed below:

Application Cylinder Head Gasket P/N ----------- ------------------------ 4.3L Engines 10105110 5.0L Engines 10105115 5.7L Engines 10105117

Parts are currently available from GMSPO.

When replacing head gaskets on vehicles under warranty, use:

Labor Ops: J0500 - Right Bank J0501 - Left Bank J0507 - Both Banks

Refer to Labor Time Guide for applicable labor times for various models.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.