Pole day was a record-setting day, as drivers officially broke the 160 mph barrier. Rookie Mario Andretti was one of the first drivers to set the pace, putting in a lap of 159.406 mph, and a four-lap average of 158.849 mph. Later, Jim Clark in the Lotus 38, became the first driver to break the 160 mph barrier. His first two laps of 160.772 mph and 160.973 mph set one-lap records. His record four-lap average of 160.729 mph tentatively put him on the pole.