I ATTENTION CATALOG USER JANUARY 1991 THE FOLLOWING CATALOG CHANGES ARE IN PLACE FOR JANUARY 1991 EFFECTIVE WITH THE 1991 MODEL YEAR SPO WILL ADHERE T0 CORPORATE UNIFORM PARTS CLASSIFICATION UPC FUNCTIONAL NAME ADDRESS FNA STANDARDS PART NAME CHANGES MAY OCCUR TO MEET THE NEW UPC FNA STANDARDS SPECIAL NOTICE THE FOLLOWING CHARTS HAVE BEEN MOVED FROM THE INFORMATION SECTION IN THE PARTS CATALOG TO THE NEW REFERENCE CATALOG 88 ABBREVIATIONS METRIC INFORMATION GM PRODUCTION OPTIONS SERVICE IDENTIFICATION LABELS THE FOLLOWING CHARTS HAVE BEEN MOVED FROM THE INFORMATION SECTION OF THE PARTS CATALOG TO THEIR PRIME GROUP ENGINE I D CODES O0 000 TRANSMISSION I D CODES O4 000 REAR AXLE I D CODES 05 386 CATALOG TEXT TO ILLUSTRATION CROSS REFERENCE ALL LIGHT TRUCK CATALOGS WILL HAVE A TEXT TO ILLUSTRATION CROSS REFERENCE IT WILL GIVE THE PAGE AND CALLOUT NUMBER I E PG 4 12 2 E THIS MEANS THE PART IS FOUND ON PAGE 4 12 CALLOUT NUMBER 2 IN THE ILLUSTRATION SECTION THIS WILL APPEAR AT THE END OF THE DESCRIPTION FIELD ILLUSTRATIONS THE CRASH ILLUSTRATIONS LOCATED IN SECTION 18 000 HAVE ALSO BEEN RETURNED BACK INTO THEIR INDIVIDUAL GROUP SECTIONS YOU MAY NOW ACCESS THE REGULAR ILLUSTRATION SECTION OR THE CRASH SECTION FOR YOUR SERVICE PARTS IDENTIFICATION NEEDS CONTINUED ON NEXT PAGE A 1991 GENERAL MOTORS SERVICE PARTS OF ERAT ONS LT TRUCK 52M L 1 91