| 1 | Lotus 40 Ford | Team Lotus | blue/red/green | | open | mid |
| 3 | McLaren Elva Mark I Oldsmobile | John Coombs | grey | | open | mid |
| 4 | McLaren Elva Mark II Oldsmobile | McLaren Cars | red | | open | mid |
| 5 | Lotus 40 Ford | A. J. Foyt | white | | open | mid |
| 6 | Brabham BT8 Climax | Kay Racing Int. | blue | | open | mid |
| 7 | Scarab Mk IV Chevrolet | Augie Pabst | dark blue (+white) | | open | mid |
| 8 | Lotus 19 Chevrolet | Alan Green | white | | open | mid |
| 10 | Genie - Ford | Hilton Racing | red | | open | mid |
| 11 | Lola T70 Chevrolet | Pacesetter Homes | blue/green | | open | mid |
| 12 | Lola T70 Ford | Haskell Automotive | blue | RUSSKIT | - | mid |
| 13 | McLaren Elva Mark I Oldsmobile | R. C. Macom | red | | - | mid |
| 14 | Lotus Elan Ford | Joe Ward | blue/red/green | | - | front |
| 15 | McKee Mk V Plymouth | Town+Country | white | Plymouth | open | mid |
| 16 | Lotus 23B Porsche | Team Ocean Motors | white | | - | mid |
| 17 | Lola T70 Ford | John Mecom | blue (+white) | | - | mid |
| 18 | Lola T70 Ford | John Mecom | blue (+dark blue/white) | ZEREX | open | mid |
| 22 | Genie - Oldsmobile | Dan Blocker | green | | - | - |
| 23 | Lotus 23 Climax | Rev-M Racing | red/white/blue | | open | mid |
| 24 | Lola T70 Chevrolet | Lola Cars Ltd. | | | - | mid |
| 25 | Lola T70 Chevrolet | Team Surtees | red | | - | mid |
| 26 | Arciero Special Climax | Arciero Bros. | red | ARCIERO Bros. | open | - |
| 29 | Lotus 19 Ford | Am-Way Racing | light bluie (+red) | | - | mid |
| 30 | Lotus 40 Ford | Team Lotus | green | | - | mid |
| 33 | Cheetah | Clarence Dixon | silver | | - | - |
| 34 | Ferrari 250 LM | Haskell Automotive | green | Haskell Automotive | - | mid |
| 36 | Lotus 30 Ford | M R M Inc. | silver | | - | mid |
| 37 | Porsche 904 GTS | Precision Motor | red | | - | mid |
| 39 | Cooper King Cobra Ford | Charles Cox | metallic blue | | open | mid |
| 41 | Lotus 23 Climax | W. F. Goodram | white | | - | mid |
| 44 | Chevette (McKee Mk II Chevrolet) | Jerry Hansen | maroon | | open | mid |
| 45 | Lola T70 Chevrolet | Harold Young | white | | open | mid |
| 55 | Cheetah - Chevrolet | Entin Bros. | blue | | - | - |
| 60 | Genie | Don Wester | yellow | | open | mid |
| 61 | Genie Mk.8 Chevrolet | Paul Reinhart | silver | | open | mid |
| 62 | Arciero Sp. | Arciero Bros. | red | | - | - |
| 65 | Chaparral 2A Chevrolet | Chaparral Cars | white | | open | mid |
| 66 | Chaparral 2C Chevrolet | Chaparral Cars | white | | open | mid |
| 67 | Elva - BMW | Bud Morley | white/blue | | - | - |
| 69 | Lola T70 Chevrolet | Stirling Moss | blue/green/red | | - | mid |
| 71 | Ford GTX-1 | Bruce McLaren | white | | - | mid |
| 74 | Genie Mk.8 | Dave Ridenour | blue/gold | | open | mid |
| 75 | Platypus - Porsche | Hans Adam | orange | | open | front |
| 77 | McLaren Elva Mark I Ford | All American | blue/white | | open | mid |
| 88 | Elva - Porsche | Vasek Polak | silver | | - | mid |
| 91 | Ford GT40 | Essex Wire Corp. | white | | closed | mid |
| 93 | AC Cobra Ford | Essex Wire Corp. | white | | - | front |
| 97 | McLaren Elva Mark I Oldsmobile | Charlie Hayes | white | | - | mid |
| 99 | Hamill SR3 Ford | Bob Johnson | blue | | - | - |
| Lotus 19 Chevrolet | Arciero Bros | | | open | mid |
| Cheetah | | | | - | - |
| Brabham BT8 Climax | | | | open | mid |
| Lotus Elan | | | | - | front |