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Decoding U.S. and Canadian Buicks

Appendix 1

To properly decode a Buick you need several pieces of information. These include:

  • The car serial number (aka., serial number, frame number, frame serial number, VIN)
  • The stamped engine serial number (on 1959 and later U.S. built engines the stamped production code should also be used).
  • Data from the trim tag.

On 1935-1955 Canadian built Buicks, a single data tag on the firewall or cowl will contain all of the required information, but on U.S. built Buicks, in general these numbers are found in the following locations:

  • Frame serial number - for 1935-1940 it is on a plate riveted to the right side (passenger side in U.S./Canada) of the frame near the battery or starter. For 1941-1948 it is on the firewall near the trim tag.
  • Car serial and VIN - on a plate attached to the left side door jamb (driver side in U.S./Canada) or on the left side of the dash near the windshield.
  • Stamped engine serial number and production code - various places on the engine depending on the engine type, see appendices 2-4.
  • Trim tag - a plate attached to the cowl or firewall under the hood.

Appendix 2 contains details on decoding 1935-1964 U.S. built cars, 1935-1966 U.S. built engines, 1935-1964 Canadian built cars, and 1951-1963 Canadian built engines. Appendix 3 contains details on decoding 1965-1966 Canadian built cars and 1964-1966 Canadian built engines. In Canada, 1964 was a transition year that used the previous car serial number format but a new engine serial number format because three different engines were built in Canada in 1964, that is why 1964 is split up in the appendices. Appendix 4 contains information on decoding 1965-1980 U.S. built cars, 1967-1980 U.S. built engines, and 1967-1980 Canadian built cars and engines. Appendix 5 contains information on paint codes and Appendix 6 contains information on trim codes. Appendix 7 contains information on option codes, trim and serial number tags, and engine number stamps. Appendix 8 contains information on the custom Excel functions written for the decoding tool.

To use the tool, open the file with Excel. The tool contains custom Excel functions, so if you receive any macro warnings make sure to enable the macros otherwise the tool will not function properly. The first worksheet contains production data, car serial number ranges, and engine serial number ranges. Car serial number ranges are calculated using the model year production and the starting serial number for each year. Where the model year production is not available, no calculation is made. For 1951-1963, the engine starting and ending serial numbers are either taken from the A.E.A. tune-up chart (ref. 1) for the given year or estimated assuming 100,001 for the first engine in 1951 and then adding the calendar year production for subsequent years. Calculated engine starting and ending serial numbers were adjusted further to match the sample data. In must be noted that the actual yearly break points for engine serial numbers for some years are not known, thus the need to make an estimate. For 1964-1966 the starting engine serial numbers are available from the Canadian Maintenance Manual for 1964 and 1965 (ref. 2) and the Chassis Service Manual for 1966 (ref. 3) and the ending engine serial numbers are not estimated.

Individual car or engine data is entered on the "1935-1942 Canadian Buicks", "1951-1966 Canadian Buicks", "1967-1980 Canadian Buicks", and "1935-1964 US Buicks" worksheets. To enter new data, either use an existing row, or copy and paste a new row. You can also insert a new row and fill down the formulas. User entered data is shown in red at the beginning of the data row. Notes and source information can be entered at the end of the data row. Sample data is provided for most years, so follow the pattern provided if you are unsure about how the data should be entered. The remaining worksheets in the file are used as lookup tables for the formulas that decode the car model, model description, production data, paint codes, and trim codes. They should only be modified by someone who is familiar with the formulas.

At a minimum, you need to enter data in the first three columns (year, car serial number, and engine serial number). You can enter either the car or engine serial number and then enter "N/A" for the other value. For the car serial number, you can enter X's for the sequential part of the number, but for the engine serial number you must enter a complete number, but omit spaces and dashes. For the actual engine type enter either "V6 225", "I8 263", "V8 264", "V8 300", "V8 322", "V8 340", "V8 364", "V8 401", "V8 425", "V8 400", "V8 430", or "V8 455" (all without quotation marks). For the actual transmission type, enter either "Automatic" or "Manual" (all without quotation marks). For the actual carburetor type enter either "1V", "2V", "4V" or "2x4V" (all without quotation marks). If you have a 1951-1953 Deluxe model, enter a "D" (without quotation marks) in the column labeled "Deluxe". For 1951-1953 Canadian built Buick's it is not possible to distinguish between standard and deluxe models based upon the car serial number alone. If you don't know if your car is a Deluxe, omit the "D" and the tool will decode the car as a standard model. For 1940 and 1960 car serial numbers, enter an apostrophe (') before the "0" for the model year otherwise Excel will truncate the leading zero and the functions will not work properly.

Discrepancies between the actual and calculated engine type, transmission type, carburetor type, and year will be highlighted in yellow using conditional formatting. For 1951-1963, engine sequential numbers outside the estimated sequential number range will be highlighted in yellow using conditional formatting. This means that the starting or ending engine sequential number needs to be adjusted on the first worksheet in the file.

If you enter the paint and trim codes the decoding tool will give the paint colors and interior trim type and colors. For trim codes with leading zeros, enter an apostrophe (') before the leading zeros otherwise Excel will truncate the leading zero and the functions will not work properly. For example, enter '001 for trim code 001 and '011 for trim code 011. You can also enter the codes for convertible tops or vinyl roofs and any option codes listed on the trim tag.

For 1951-1966, the model year is calculated by a custom Excel function, which is contained on the macro module Buick_Functions (thus the reason for the macro warnings when Excel was opened). This is a very complex calculation because the first digit of the car serial number that represents the year is repeated for each decade, i.e., 4 = 1954 and 1964, and because of the changes to the engine serial number format in 1964 and the car serial number format in 1965. If the car serial number is given it will be used to determine the year the car was built. If the car serial number is not available, the engine serial number will be used. If you don't know the year, enter the car serial number and/or the engine serial number and then look at the result in the column labeled "Calculated Year", this value can be used in the "Year" column at the beginning of the row. A list of all custom functions contained in the decoding tool can be found in Appendix 8.

Compiled with information contributed by Buford26 - SOURCES UNKNOWN