SPARK PLUG USAGE UPDATE PRODUCTION CHANGE- P/N

Model and Year: 1988 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H AND K)

Some 1988 trucks with 4.3L, 5.0L and 5.7L engines may experience a popping noise in the radio due to the use of AC CR43TS spark plugs. This condition can be repaired by replacing the CR43TS plugs with R43TS plugs (P/N 5613325). R43TS plugs entered production with engines produced since August 30, 1987. Spark plug gap specification is 0.035".

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.