Ferrari: Once again, Mario Andretti was at a conflicting USAC event. The cars were unchanged from Germany.
Lotus: the only changes were slight modifications to the rear driveshafts, trying to alleviate wheel vibration.
March: No changes to the cars, but Niki Lauda made his Formula One debut as a rental driver.
Since the Nürburgring, the Henri Pescarolo entry had been almost completely rebuilt.
Since the Nürburgring, the Mike Beuttler entry had had the monococque and suspension strengthened and reinforced.
Matra: The team skipped this race to concentrate on badly needed development work.
McLaren: Peter Gethin had been released from his contract, after increasing acrimony on both sides. Jackie Oliver was the new second driver, and as an experiment, his car had been modified with M14-design rear suspension.
Surtees: John Surtees drove the newest car. Rolf Stommelen had been unhappy with the handling of his car at Nürburgring, so Surtees gave Stommelen his old car, and Stommelen's old car became the spare.
Tyrrell: On Friday the team had modified Jackie Stewart's car with a 9 cm spacer between the engine and gearbox, to alter the weight distribution and polar moment of inertia, and aid in handling on longer radius corners. The team gathered a large amount of data before reverting to normal specifications for Saturday practice and the race. Otherwise the cars were unchanged.