| 1 | Siffert / Elford / *Buzzetta | Porsche System Engineering, Ltd. (D) | | Porsche | 908 | Coupe | Porsche | P3.0 |
| 2 | Herrmann / Ikuzawa / Siffert / *Attwood | Porsche System Engineering, Ltd. (D) | | Porsche | 908 | Coupe | Porsche | P3.0 |
| 3 | Patrick / Attwood / Buzzetta / *Siffert / *Ikuzawa | Porsche System Engineering, Ltd. (D) | | Porsche | 908 | Coupe | Porsche | P3.0 |
| 4 | Follmer / Buzzetta | Porsche System Engineering, Ltd. (D) | | Porsche | 908 | Coupe | Porsche | P3.0 |
| 5 | Bianchi / Ickx | J. W. Automotive Engineering, Ltd. (GB) | | Ford | GT40 | | Ford | S5.0 |
| 6 | Hawkins / Hobbs | J. W. Automotive Engineering, Ltd. (GB) | | Ford | GT40 | | Ford | S5.0 |
| 7 | Wonder / Cuomo / Caldwell | William M. Wonder, Inc. (USA) | William Wonder | Ford | GT40 | | Ford | S5.0 |
| 9 | Yenko / Morgan | Sunray-DX Oil Co. (USA) | | Chevrolet | Corvette | C3 | Chevrolet | GT+2.0 |
| 10 | Woolfe / Piper | John Woolfe Racing (GB) | John Woolfe | Chevron | B12 | | Repco | P3.0 |
| 11 | Bonnier / Parsons / *Axelsson | Ecurie Bonnier (CH) | Joakim Bonnier | Lola | T70 | Mk.3 GT | Chevrolet | S5.0 |
| 12 | Johnson / Johnson | Robert Johnson (USA) | Robert Johnson | Chevrolet | Corvette | C3 | Chevrolet | GT+2.0 |
| 14 | Bailey / Locke | B & B Motors. Ltd. (USA) | Robert Bailey | Porsche | 906 | LH | Porsche | S2.0 |
| 21 | Kolb / Rodriguez / *Grossman | North American Racing Team (Luigi Chinetti, Sr.) (USA) | Luigi Chinetti, Sr. | Ferrari | Dino 206 S | Coupé | Ferrari | P2.0 |
| 22 | Grossman / Bucknum / *Unser | North American Racing Team (Luigi Chinetti, Sr.) (USA) | Luigi Chinetti, Sr. | Ferrari | 275 GTB | /4 | Ferrari | S5.0 |
| 33 | Kwech / Martino | Ausca Racing, Inc. (USA) | Horst Kwech | Alfa Romeo | T33/2 | | Alfa Romeo | P2.0 |
| 37 | Oest / Davidson | Dieter Oest (USA) | | Porsche | 904 | GTS | Porsche | S2.0 |
| 47 | Prefontaine / Roberts | Andre Prefontaine (USA) | Andre Prefontaine | Lotus | 47 | | Ford | S2.0 |
| 58 | Duval / Ostiguy | Jacques Duval (CDN) | | Porsche | 906 | | Porsche | S2.0 |
| 59 | Everett / Gregg | Brumos Porsche Corp. (USA) | | Porsche | 911 | T | Porsche | GT2.0 |
| 67 | Dibley / Tullius | Howmet Corporation (USA) | Hugh Dibley | Howmet | TX | | Continental | P3.0 |
| 73 | Baker / Richards / Baker | Baker Motor Co., Inc. (USA) | Jim Baker | Austin-Healey | Sprite | | BMC | P2.0 |
| 76 | Thompson / Heppenstall | Howmet Corporation (USA) | | Howmet | TX | | Continental | P3.0 |
| 86 | Hill / Brack | Sports Cars Unlimited, W. Clarkson (CDN) | W. Clarkson | Triumph | GT6 | | Triumph | GT2.0 |
| 88 | Frank / Trieschmann | Foreign Car Sales (USA) | Werner Frank | Porsche | 906 | E | Porsche | S2.0 |
| 93 | Mollin / Riley | Arthur Mollin Racing (USA) | Arthur Mollin | TVR | Grantura | Mk IV | BMC | S2.0 |
| 94 | Meaney / Dearborn | Ralph Meaney (USA) | Ralph Meaney | Porsche | 911 | | Porsche | GT2.0 |
| 97 | Herrington / Mansfield / Walsh | Herrington Motors, Inc. (USA) | William J. Herrington | MG | B | GT | BMC | GT2.0 |
| 99 | Finkel / Sutter / *Nagel | Pegasus Racing Team (USA) | | Shelby | GT350 | R | Ford | GT+2.0 |