GENERAL INFORMATION Complete familiarity with the information on these pages as well as the general layout of the Parts Book will prove helpful in locating and ordering the desired parts The Book is arranged in sections as follows Model Series Information Alphabetical Index Chassis Parts Listing Groups 0 000 to 9 000 inclusive Body Parts Listing Groups 16 000 to 17 999 inclusive Numerical Index The Grouping System for cataloging parts is used as follows Main units of the vehicle are identified by a Numerical value preceding the Decimal i e Engine 0 Cooling and Oiling 1 Electrical 2 Fuel System 3 Some Parts may be cataloged somewhere other than its original or prime group In such listings the prime group is indicated in parenthesis procedure is necessary since a part can have but one identifying Group Number for ordering or bin location READING TRUCK CATALOG FORMAT The Truck Models included in this publication are listed as follows M 2 WHEEL DRIVE 109 STANDARD BODY L ALL WHEEL DRIVE 110 EXTENDED BODY For further clarification see the Truck Series Identification Charts which follow the General Information Section of the catalog 1990 93 TRUCK CATALOG FORMAT The 1990 93 truck catalog format is written in a similar way to that of the passenger car catalog using model codes in place body styles RPO Regular Pro duction Options wil also in most cases be called out in code w description where needed Refer to the RPO list for proper identification of RPO s WHEELBASE When the wheelbase dimension is essential to differentiate between models a 3 digit model number will be used For a full explanation on decoding the model code and wheelbase refer to the truck series identification chart When using the dimensions and other data shown in the Description Column the Parts Manager should be guided by the following 1 length overall refers to the total length of a part measured over the longest dimension An irregular shaped piece is measured over the longest dimension regardless of contours and bends 2 dev length refers to the total length of a Bart such as a tail pipe or gas pipe measured as though the part were straig tened out This measurement can be taken on formed pipes by using a string to follow the contours of the pipe and then measuring the leng h of string used 3 I D refers to the inside diameter O D refers to the outside diameter O S refers to oversize U S refers to undersize 1 1992 GENERAL MOTORS SERVICE PARTSOPERATIONS LIGHT TRUCK 53M 8 92 at