I searched through the Tech-Tip linked above and could not find the word
"serial", or the term "serial number"" in it.
The term VIN for Vehicle Identification Number is used in the Tech Tip. This is not a term used by GM in reference to older trucks (the term
VIN has definitive meaning for all vehicles built after 1980 ).
In 1940, GM used the term
Unit Serial Number. In 1954, the VID plate (Vehicle Identification Plate) contained the
Vehicle/Unit Serial Number (GM terminology). In 1954, GM also made reference to engine, transmission, and rear-end serial numbers (displayed at the previous link and
in the Shop Manual).
As mentioned above, the term VIN is a more modern term and it has no exact meaning relative to most pre-1955 trucks (at least).
My experience with dealing with only about six 47-55 trucks (GMC and Chevrolet) from four different states is that 50% were titled with the engine serial number (GM terminology) and 50% with the VID code (GM terminology for the plate between the hinges on the driver's side). In addition, in two of the states, I obtained old titles that used the engine serial number for one truck and the VID-plate Vehicle Serial Number for another truck. New York state does not care what you use as the "VIN", as long as you pay the sales tax.
