The last iteration of the 500 racer appeared during 1973, with belt driven double overhead camshafts, and a radial finned front cylinder. The camshaft belts were on the opposite side to the bevel gear shaft drives on earlier engines. The engine had been developed for Taglioni outside Ducati by Armaroli, and featured the reversed head layout found in the later Paso where the inlet ports face each other. It produced at 12,000 rpm, not a big increase. MV continued to win. In 1971 and 1972 the 500s, and later the 750s, were raced and displayed throughout the western world as part of a major publicity exercise to promote the Ducati name.