| 1 | Brett Lunger | Autodynamics Corporation (USA) | Caldwell | D7 | Chevrolet |
| 2 | Sam Posey | Autodynamics Corporation (USA) | Lola | T160 | Chevrolet |
| 4 | Bruce McLaren | McLaren Cars Ltd. (GB) | McLaren | M8A | Chevrolet |
| 5 | Denny Hulme | McLaren Cars Ltd. (GB) | McLaren | M8A | Chevrolet |
| 6 | Mark Donohue | Roger Penske Racing Ent. (USA) | McLaren | M6B | Chevrolet |
| 7 | John Surtees | Team Surtees (GB) | Lola | T160 | Chevrolet |
| 9 | Jo Bonnier | Ecurie Suisse (CH) | McLaren | M6B | Chevrolet |
| 10 | Chuck Parsons | Carl A. Haas Racing Teams, Ltd. (USA) | Lola | T160 | Chevrolet |
| 11 | Lothar Motschenbacher | Leader Cards Racers (USA) | McLaren | M6B | Ford |
| 14 | Lynn Kysar | Homer J. Rader (USA) | Lola | T70 Mk.3 | Chevrolet |
| 15 | Brian O'Neil | American Racing Motors (USA) | Lola | T70 Mk.3B | Chevrolet |
| 18 | Ron Courtney | Ronald K. Courtney (USA) | McLaren | Elva Mark III | Chevrolet |
| 20 | Anson Johnson | American Racing Motors (USA) | Lola | T70 Mk.3B | Chevrolet |
| 21 | Mario Andretti | Bignotti Enterprises (USA) | Lola | T70 Mk.3 | Ford |
| 22 | Pedro Rodriguez | North American Racing Team (USA) | Ferrari | 330 P4 | Ferrari |
| 24 | Bob Nagel | Bob Nagel (USA) | Lola | T70 Mk.3 | Ford |
| 26 | Skip Scott | Carl A. Haas Racing Teams, Ltd. (USA) | Lola | T160 | Chevrolet |
| 28 | Dick Brown | Ecurie Green Inc. (USA) | McLaren | M6B | Chevrolet |
| 31 | Ronnie Bucknum | Agapiou Racing (USA) | Lola | T70 Mk.3B | Ford |
| 36 | Swede Savage | All American Racers (USA) | Lola | T160 | Ford |
| 37 | George Ralph | George L. Ralph (USA) | Lola | T70 Mk.2 | Chevrolet |
| 42 | Candido DaMota | Land & Cattle Inc. (USA) | McLaren | Elva Mark III | Chevrolet |
| 43 | Fred Pipin | Jack Douglas Chevrolet (USA) | Lola | T70 Mk.3 | Chevrolet |
| 44 | Jerry Hansen | Jerry Hansen (USA) | McLaren | M6A | Chevrolet |
| 48 | Dan Gurney | All American Racers (USA) | McLaren | M6B | Ford |
| 52 | Peter Revson | Shelby Racing Co., Inc. (USA) | McLaren | M6B | Ford |
| 66 | Jim Hall | Chaparral Cars Inc. (USA) | Chaparral | 2G | Chevrolet |
| 98 | George Eaton | George Eaton Racing (CDN) | McLaren | Elva Mark III | Ford |