On the models above, the rear axle is narrower by 8 inches than the front. Due to stack up of parts, the rear axle may set off to one side or the other (K10 up to 1 3/4 inches, left or right), (K30 up to 2 1/4 inches left or right).
This condition will not cause abnormal tire wear (as tires are parallel front to rear) nor will it affect handling.
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.