Owners of some 1991 C/K, R/V/G/P, C5H, C6H, and C7H trucks with 6.OL, 7.OL, or 7.4L engines may experience a valve rocker arm bolt failure because one manufacturer of this rocker arm bolt had forming cracks at the shoulder of the bolt.
Although the frequency of this type of failure will be very low, GM is suggesting that if this occurs, all bolts identified as shown in the illustration below be replaced with P/N #10114123.
Parts are currently available from GMSPO.
Use applicable labor operations and times.
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.