Some 1985-86 P-3 models equipped with a 7.4L engine and H5D emissions may exhibit the left exhaust manifold pipe contacting the oil filter. This condition was corrected effective S.O.P. 1987, with the release of a redesigned exhaust manifold pipe. This new pipe design provides increased clearances between the oil filter and the exhaust pipe.
This new exhaust manifold pipe, P/N 1555-9924, may be obtained through GMSPO and may be used on earlier production vehicles manufactured with a 7.4L engine and H5D emissions.
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.