In 1973 the Barcelona 24-hour race was won by Canellas and Grau on a round case Ducati 750 SS converted into an 860 by the use of the Ducati 450 single-cylinder engine's sleeves and pistons. In 1974, the 860 GT went into production. The crankcases had been redesigned by Giugiaro, along with the rest of the bike, with a squared off look, quite unlike the flowing lines of the 750. The new boss De Eccher saw Ducati's future in US exports, and had engaged Giorgetto Giugiaro to do the external design work on the new 860 instead of Tartarini. Taglioni was made to redesign the outer engine cases to match Giugiaro's design. (The new 350 and 500 GTL sport vertical twins were also released, also externally designed by Giugiaro. The motors were not built by Taglioni. He had refused to be involved with them.)