set about improving the 512. Widened by 100mm, with an improved and lightened aerodynamic chassis, the V12 engine was also uprated to produce 580 bhp. The new version, the 512M (modificato) debuted at the end of the 1970 season with a win to Ickx/Giunti. The 512M modifications were offered to the customer teams, but not applied to the works cars as Ferrari had decided to give up any official effort with the 512 in order to prepare the new 312PB for 1972. Between them, the customer teams put up a competent challenge to Porsche. The North American Racing Team (NART) had three entries. The Penske team, very competitive at the American rounds of the championship, arrived on one of the NART entry tickets. Their chassis was made by Holman & Moody and the engine prepared by Can-Am V8 specialist Traco (claiming 614 bhp). A number of quick-change modifications were added for wheels, brakes and refuelling to save valuable minutes in the pits. The blue, Sunoco-sponsored, car was driven by Mark Donohue/David Hobbs. The regular NART 512M also had a Traco engine and was driven by Sam Posey/Tony Adamowicz. And there was an open-top, spyder, version was for Masten Gregory/George Eaton. The Scuderia Filipinetti also entered a much-modified Ferrari. Known as the "512F", it was designed by former Ferrari racing engineer/driver Mike Parkes it had a bigger rear-wing and used the Porsche 917 windscreen which was 120mm narrower, allowing for better water- and oil-cooler placement. With regular co-driver Jo Bonnier unavailable for personal reason, Henri Pescarolo was brought in as his co-driver. José Juncadella of Escuderia Montjuich had employed 1964-winner Nino Vaccarella. Ecurie Francorchamps, Georg Loos and Corrado Manfredini also returned with their modified cars. David Piper's entry was used by American privateer David Weir who had bought the spare car off Steve McQueen's Solar Productions film company. Just after the 1970 Le Mans, Chrysler completed the takeover of Simca creating Chrysler Europe, and this also meant the Matra company was renamed Matra-Simca. Matra entered only one 660 for its F1 drivers Chris Amon and Jean-Pierre Beltoise. Beltoise had recently recovered his racing license after investigation in an accident at January's Buenos Aires 1000km that had killed Ferrari driver Ignazio Giunti. After a poor race the previous year, the engine was strengthened and now put out 420 bhp. While Guy Ligier's GT car was on hold pending homologation, he entered a