stable powertrain contract with General Motors, the company began the production of a new lineup of models based on the GT 300 chassis (standard, extended or shortened). The result was the Grifo sports coupé (1965), with engines from 5.4 to 7 liters, the Fidia luxury saloon (1968) and the Lele 2+2 grand tourer (1969) designed by Marcello Gandini, chief designer at Bertone. By the end of 1971, due to the unfavorable economic conditions imposed by GM (demanding advance payment for the engines, which had to be purchased in bloc), the company adopted Ford Cleveland engines. Competition from prestigious brands, especially Maserati and Aston Martin (but also, for some models, Ferrari and Lamborghini), and the oil crisis of 1973, put Iso Rivolta in financial jeopardy. At the beginning of 1973, the Rivolta family listed the company on the New York Stock Exchange. An agreement with Philip Morris and the young team manager Frank Williams led to the formation of the Iso-Marlboro Formula 1 team (the original name of Frank Williams Racing Cars). The business name of the company changed to Iso Motors & Co. due to the raking in of the stock exchange shares made by the Italian-American Iso Pera. After producing 10,000 ISO snowmobiles, the Rivolta family eventually gave up ownership. The costs of managing the team, the drop in sales due to the economic and social crises in the first half of the 1970s and conditions in the U.S. market (where the company was late in obtaining the status of "Small Manufacturer," which applied less stringent sanctions standards) led to the end of car production on December 31, 1974. ORSA 850 Spring Special In anticipation of the impact of the oil crisis on granturismo cars, the Rivolta family decided at the end of 1972 to partner with the ORSA company, a modest industrial plant founded by a small group of Sardinian entrepreneurs on the outskirts of Cagliari, equipped for the small-scale construction of retro-style open cars. For this purpose, the Spring model assembly lines were taken over from SIATA, which had closed its doors. Since the Fiat 850, on whose chassis the Siata Spring was built, was no longer in production, an agreement was made with SEAT, which was still building it in Spain. Legacy The "'Museo ISO Rivolta" is a project that has been in development for years, with a plan to inhabit the former warehouses of the