Complete familiarity with the information contained on these pages as well the general layout Of thc Parts Catalogs will prove helpful in locating and ordering the desired parts Th hevmlet pans and Accessories Catalogs are arranged in sections as follows Model Series Identification Alphabetical Index Chassis Parts Listing groups 0 000 to 9 999 inclusive Passenger Body Parts Listing groups 10 000 to 15 999 uSiV Commercial Body Parts Listing groups 16 000 to 17 9Snc usiV The Group System of listing parts is used and briefly is as follows Main units of the car are identified by the Numeral preceding the Decimal i e Engine Cooling and Oiling Electrical Fuel System t Individual Parts are assigned a Group Number the first Numeral identifying the ma unit it is affiliated with and following the Decimal is the Sub Group Number under which all Parts of the samqamc and function are listed For instance Group 0 033 0 indicates that it is an Engine Part 033 is theocatgcn where all Part Numbers of Cylinder Blocks now being serviced may be found For convenience List Price is shown where the Part is listed Some Parts may be listed GIS here than in its original or prime Group and in such listings the prime Group is indicated in parentheses Us procedure is necessary as a part can have but one identifying Group Number for ordering or bin location Fonxamplcl under Group Number 3 751 Part Number 342146 is listed as Carburetor Choke Valve Screw and the gmc Group 3 761 is shown in the description column When using the dimensions and other data shown in the Description Column the parts manayi Should be guided by the following 1 length overall refers to the total length of a part measured over the longest dimension I irregular shaped piece is measured over the longest dimension regardless of contours and bends 2 dev length refers to the total length of a part such as a tail pipe or gas pipe measured as thugh the part were straightened out This measurement can be taken on formed pipes by using a string tl follow the contours of the pipe and then measuring the length of string used 3 l D refers to inside diameter O D refers to outside diameter O S refers to oversize l S refers to undersize To locate the listing of a Part determine the model vehicle and refer to the Book under the Group Nurrber identifying it which may be determined by using any of the following three methods 1 Consult Alphabetical Index at front of book which lists Parts by noun and descriptive names and refers to the exact Group Number where all Parts of similar kind may be found More than one Group Number will be given where the same kind of part is shown in both Passenger and Commercial Body sections lf Name of desired Part is not readily found in the Index a correlated Part Name will suggest approximate location 2 Consult Illustrations in this publication on which Group Numbers Part Numbers and Noun Name are shown which will refer to the Part or Assembly wanted On Illustrations where both left and right part numbers are listed the first number will always designate left hand side 3 Consult Dealer Parts and Accessories Price Schedule if a Part Number is known and use its Group Number to locate a similar Part or be directed to the approximate location of correlated Parts The column headed No Used indicates the number of pieces required The term A R means As Flequired lf Body is not of Chevrolet manufacture place orders direct with the manufacturer whose name appears on the Body Name Plate 1974 GM PARTS DIVISION GENERAL MOTORS CORPORATION CHEVROLET P A 30B 4