Transam continued to grow. More races (13), more money, more spectators. A big fight between Ford and Chevrolet was expected, with the new AMC team as a dark horse - but it turned out differently.
AMC tried hard and got some encouraging results (6 second places) but no win. Ford made the mistake of the age to settle for the tunnel-port engine, which was a disaster - no power, no reliability. At the end of the season, things started to improve when Shelby prepared its own engines, but it was too late by then. The championship was lost to Chevrolet, with Penske's beautifully prepared cars and Donohue winning 9 races, of which 8 in a row.
The U-2000 class was won by Porsche with a wide margin (9 race wins here too), the best driver being Adamowicz with 6 wins.