* Check the Vehicle Identification Number (VIN): The VIN plate, usually located on the dashboard or doorjamb, contains a code that can be deciphered to determine the engine. However, Pontiac's VIN system from 1963 isn't as straightforward as later systems; you'll likely need a Pontiac VIN decoder specific to that year. Many online resources are available, but you'll need the full VIN.
* Look at the Engine Block: The engine itself will usually have a casting number stamped on the block. This number can be cross-referenced with Pontiac engine casting number databases or manuals to identify the engine displacement (e.g., 389 cubic inches, 326 cubic inches, etc.). This requires some hands-on work and familiarity with engine components.
* Examine the Original Documentation: If you have the original owner's manual or other paperwork for the car, it will almost certainly specify the engine size.
* Check the Build Sheet (if available): A build sheet is a document that details the specifications of the car as it was built. These are rare, and highly prized by collectors. If you have one, it will be a definitive source of information.
Which method is best?
Starting with the VIN decoder is probably the easiest if you have the VIN readily available. Checking the engine block is the most direct but requires access to the engine and some mechanical knowledge. The other methods depend on the availability of documentation.
