I know a little about the Canadian cars from what I've read, but not sure on what the differences are. -especially the later cars. If this is the same layout as an early "Big" Canadian Pontiac then it has a Chevrolet chassis, floorpan and interior pieces. Here is a link I stumbled on a while ago of some details and a '64 Parisienne Custom Sport 425HP 409, 4-Speed.
A Bruneau Performance Ent. Click on ENTER, then 1964 Pontiac (under the pic) and then Parisienne Custom Sport for one of his mentions about the platform.