either Chevrolet-Oldsmobile-Cadillac or Pontiac-Buick-GMC; small towns usually had only one or the other, but not both, so it was imperative to keep Pontiac prices competitive with Plymouth and Ford (and Chevrolet). Producing two entirely separate engine series would have increased costs, so the Chevrolet straight-six replaced the Pontiac Flathead Six, and the new Chevrolet V8 replaced the old Pontiac straight-eight. In 1958, the "Strato-Chief" replaced the "Pathfinder Deluxe", and in 1959 the line was reorganized with "Laurentian" in mid-range and the new "Parisienne" inserted at the top (similar to the U.S. market Bonneville). Even after the Canadian market was opened by the signing of the 1965 Autopact the Canadian full-sized Pontiac lineup—and the practice of building them on Chevrolet chassis with Chevrolet engines—continued mostly unchanged into the 1980s (although the Strato-Chief was dropped in 1970). GM Canada also built right-hand drive versions of their Pontiacs for export to Australia, New Zealand, and South Africa as knock-down kits until the late 1960s. The interiors of these cars more closely resembled the equivalent Chevrolets than the Canadian market cars did, as the Chevys had already been designed for right-hand drive. When the compact Chevrolet Corvair and Pontiac Tempest were introduced in 1960 the Corvair was built in Canada, but the Tempest was not. Importing the Tempest into Canada from the United States was not a viable option as the duties that would have had to have been paid would have substantially increased the price of what was supposed to be the least-expensive Pontiac. Tentative plans to build a Pontiac version of the Corvair were scrapped when the more conventional Chevy II was introduced in late-1961. GM Canada developed a new brand exclusively for the Canadian market for their rebadged Chevy IIs, the Acadian. Acadians were sold alongside the rest of the Pontiac lineup at Pontiac-Buick-GMC dealerships until 1971. When the mid-sized Chevrolet Chevelle was introduced in 1964 it was sold in Canada as the Acadian Beaumont ('Beaumont' was formerly the top-level trim of Chevy II-based Acadian), and in 1966 Beaumont became its own marque. The Beaumont-badged Chevelles were in production in Canada until 1969. Even after the 1965 Autopact (and Canada–United States Free Trade Agreement that replaced it in 1988), the practice of building Pontiac-badged Chevrolets for sale at Canadian dealers continued until the brand was discontinued in 2010. Such cars include the Astre (based on the Vega), the Acadian (based on