1984 87 TRUCK MANUFACTURING SOURCE x TRANSMISSION STAMPING INFORMATION Source stamping information for the 1984 87 Truck Transmission consists of five 5 characters two 2 alpha and three 3 numeric as shown below POSITION 1 MANUFACTURING SOURCE CODE The following alpha codes will be stamped in the first ist position identifying the Manufacturing Source CODE MANUFACTURING SOURCE TYPE B Parma CBC J GM of Canada CBC K Muncie Four 4 Speed 70 mm Light Duty N Muncie Four 4 Speed 117 mm Truck R Muncie Four 4 Speed 76 mm Light Duty S Muncie Three 3 Speed 75 mm Light Duty Y Toledo CBC POSITION 2 MODEL YEAR The number 4 four will be stamped in the second 2nd position for model year 1984 POSITION 3 CALENDAR MONTH PRODUCED The following alpha codes will be stamped in the third 3rd position identifying the calendar month pro duced CODE MONTH A January B February C March D April E May H June K July M August P September R October S November T December WAREHOUSING AND DISTRIBUTION DIVISION OF GENERAL MOTORS CORPORATION LT TRUCK 52D REV 10 86 15