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Pathfinder, Laurentian and Parisienne were the three models of the Pontiac in 1963. There was an American that year called the Catallina but was not sold in Canada. All three Canadian models had orange painted engines made by the Chevy engine plant while American made engines of that era were blue.
There are references to a 283 V8.
Basically it is a Canadian Bonneville.
This car has the chevy xframe not the wide track perimeter frame.
There is a 1963 Pontiac VIN decoder at: 1963 Pontiac.com