| 1 | Johnson / Morgan / *Sevadjian | Ridgeway Racing, Inc. (USA) | | Chevrolet | Corvette Grand Sport | | Chevrolet | P+4.0 | GTP |
| 2 | Wintersteen / Goetz / Diehl | George Wintersteen (USA) | | Chevrolet | Corvette Grand Sport | | Chevrolet | P+4.0 | GTP |
| 3 | Hall / Sharp | Chaparral Cars (USA) | | Chaparral | 2A | | Chevrolet | SR+2.0 | Sports |
| 4 | Hissom / Jennings | Chaparral Cars (USA) | | Chaparral | 2A | | Chevrolet | SR+2.0 | Sports |
| 5 | Robertson / Boo | George Robertson Jr. (USA) | | Chevrolet | Corvette Sting Ray | C2 | Chevrolet | GT+5.0 | GT III |
| 6 | Yenko / Bushell | Ken Hablow (USA) | Kenneth G. Hablow | Chevrolet | Corvette Sting Ray | C2 | Chevrolet | GT+5.0 | GT III |
| 7 | Wybenga / Jackson | Jack Wybenga (USA) | | Chevrolet | Corvette Sting Ray | C2 | Chevrolet | GT+5.0 | GT III |
| 8 | Moser / Casoni / *Greenblatt | Bizzarini Automobili (I) | | Iso | Grifo A3C | | Chevrolet | P+4.0 | GTP |
| 9 | Rainville / Gammino | Bizzarini Automobili (I) | | Iso | Grifo A3C | | Chevrolet | P+4.0 | GTP |
| 10 | Ginther / Hill / *Miles | Ken Miles (USA) | | Ford | GT40 | | Ford | P+4.0 | GTP |
| 11 | Miles / McLaren | Al Dowd (USA) | | Ford | GT40 | | Ford | P+4.0 | GTP |
| 12 | Leslie / Grant | Shelby-American, Inc. (USA) | | Shelby | Cobra Daytona Coupe | | Ford | GT5.0 | GT III |
| 14 | Johnson / Payne | Shelby-American, Inc. (USA) | | Shelby | Cobra Daytona Coupe | | Ford | GT5.0 | GT III |
| 15 | Bondurant / Schlesser | Shelby-American, Inc. (USA) | | Shelby | Cobra Daytona Coupe | | Ford | GT5.0 | GT III |
| 16 | Spencer / Adams / Hill | Shelby-American, Inc. (USA) | | Shelby | Cobra Daytona Coupe | | Ford | GT5.0 | GT III |
| 17 | Thompson / Shaw | Shaw Racing Team (USA) | | Shelby | Cobra | | Ford | GT5.0 | GT III |
| 18 | Lowther / Nagel / *Sinkel | Ed Lowther (USA) | | Shelby | Cobra | | Ford | GT5.0 | GT III |
| 19 | Harrison / Coleman | Arthur Harrison (USA) | Arthur Harrison | Shelby | Cobra | | Ford | GT5.0 | GT III |
| 20 | Reed / Gerber | Gerber-Payne Ford (USA) | | Shelby | Cobra | | Ford | GT5.0 | GT III |
| 21 | Decker / Koveleski | Greenwich Autos, Inc. (USA) | | Cooper | Monaco | T61 | Ford | SR+2.0 | Sports |
| 22 | Cannon / Saunders | Mecom Racing Team (USA) | John Mecom, Jr. | Lola | T70 | Mk.1 | Ford | SR+2.0 | Sports |
| 23 | Gurney / Grant | All American Racers, Inc. (USA) | | Lotus | 19 | J | Ford | SR+2.0 | Sports |
| 25 | Hull / Kingham / *Vega | Jaguar Car, Inc. (USA) | | Jaguar | E-type | | Jaguar | GT4.0 | GT III |
| 26 | Grossman / Hudson | Scuderia Bear (Ferrari Owners Racing Association) (USA) | | Ferrari | 330 P | | Ferrari | P4.0 | GTP |
| 27 | Kolb / Fulp / *McCluskey | John Fulp (Ferrari Owners Racing Association) (USA) | | Ferrari | 330 P | | Ferrari | P4.0 | GTP |
| 28 | Robson / Baggely | Richard B. Robson, Jr. (USA) | Richard Robson | Jaguar | E-type | | Jaguar | GT4.0 | GT III |
| 29 | Hansgen / Donohue | Mecom Racing Team (USA) | | Ferrari | 250 LM | | Ferrari | P4.0 | GTP |
| 30 | Rodriguez / Hill | Mecom Racing Team (Ferrari Owners Racing Association) (USA) | | Ferrari | 330 P | | Ferrari | SR+2.0 | Sports |
| 31 | Piper / Maggs | David Piper (Auto Racing) Ltd. (GB) | David Piper | Ferrari | 250 LM | | Ferrari | P4.0 | GTP |
| 32 | Hugus / O'Brien / Hayes / Richards | Ed Hugus (Ferrari Owners Racing Association) (USA) | | Ferrari | 275 P | | Ferrari | P4.0 | GTP |
| 33 | Maglioli / Baghetti | Kleiner Racing Enterprises (Ferrari Owners Racing Association) (USA) | | Ferrari | 275 P | | Ferrari | SR+2.0 | Sports |
| 34 | Hawkins / Banks | Donald Healey Motor Co. (GB) | | Austin-Healey | 3000 | | BMC | GT3.0 | GT III |
| 35 | Scott / Clarke / *Lund | Peter Clarke (GB) | Peter Clarke | Ferrari | 250 GTO | | Ferrari | GT3.0 | GT III |
| 37 | Martin / Hill | M. Barry Martin (CDN) | | Triumph | TR4 | | Triumph | GT2.5 | GT III |
| 38 | Mitter / Linge | Porsche Automobile Co. (D) | | Porsche | 904 | /8 | Porsche | P2.0 | GTP |
| 39 | Buzzetta / Pon | Porsche Automobile Co. (D) | | Porsche | 904 | GTS | Porsche | GT2.0 | GT II |
| 40 | Underwood / Klass | Porsche Automobile Co. (D) | | Porsche | 904 | GTS | Porsche | GT2.0 | GT II |
| 41 | Patrick / Jordan | Precision Motors (USA) | | Porsche | 904 | GTS | Porsche | GT2.0 | GT II |
| 42 | Lane / Cassel / *Sesslar | Carl W. Lindell Co. (USA) | | Porsche | 904 | GTS | Porsche | GT2.0 | GT II |
| 43 | Ryan / Tidwell | R.B.M. Motors (USA) | | Porsche | 904 | GTS | Porsche | GT2.0 | GT II |
| 44 | Cunningham / Fitch / Bencker | Briggs Cunningham (USA) | | Porsche | 904 | GTS | Porsche | GT2.0 | GT II |
| 45 | Barber / Gregg | Lt. Peter Gregg (USA) | | Porsche | 904 | GTS | Porsche | GT2.0 | GT II |
| 46 | Swanson / Ennis / *Layman | Arthur A. Swanson (USA) | | Abarth-Simca | 2000 GT | | Simca | GT2.0 | GT II |
| 47 | Wagstaff / Porter | Faza Motorsport (USA) | | Abarth-Simca | 2000 GT | | Simca | GT2.0 | GT II |
| 48 | Picard / Pease | British Motor Corp. (GB) | | MG | B | | BMC | GT2.0 | GT II |
| 49 | Morrill / Brennan | British Motor Corp. (GB) | | MG | B | | BMC | P2.0 | GTP |
| 50 | Wrottesley / Taylor | Abglian Racing Dev. (GB) | | Elva | Mk VIII | | BMW | P2.0 | GTP |
| 51 | Riley / Cone | Art Riley (USA) | | Volvo | P1800 | A | Volvo | GT2.0 | GT II |
| 52 | Walsh / Browne / Keith | Ginetta Cars, Ltd. (GB) | | Ginetta | G4 | R | Ford | P2.0 | GTP |
| 53 | Cuomo / Bentley | Competition Components, Inc. (USA) | | Beach | Mk.8 | | Ford | P2.0 | GTP |
| 54 | McClain / Dieas | David H. McClain (USA) | | Porsche | 356 | C 1600 SC | Porsche | GT1.6 | GT II |
| 55 | Andrey / Stoddard | Autodelta S.p.A. (I) | | Alfa Romeo | Giulia TZ | | Alfa Romeo | GT1.6 | GT II |
| 56 | Bussinello / de Adamich | Autodelta S.p.A. (I) | | Alfa Romeo | Giulia TZ | | Alfa Romeo | GT1.6 | GT II |
| 57 | Deserti / Zeccoli | Autodelta S.p.A. (I) | | Alfa Romeo | Giulia TZ | | Alfa Romeo | GT1.6 | GT II |
| 58 | Rolland / Consten | Autodelta S.p.A. (I) | | Alfa Romeo | Giulia TZ | | Alfa Romeo | GT1.6 | GT II |
| 59 | Pulver / Pruyn / Davis | Duchess Auto, Inc. (USA) | | Lotus | Elan | 26 Racing | Ford | GT1.6 | GT II |
| 60 | Rogers / Waltman | Turner Cars, Ltd. (GB) | | Turner | Sprint | Special | | P2.0 | GTP |
| 61 | Baker / Aaltonen | Donald Healey Motor Co. (GB) | | Austin-Healey | Sebring Sprite | | BMC | P2.0 | GTP |
| 62 | Hopkirk / Mäkinen | Donald Healey Motor Co. (GB) | | Austin-Healey | Sebring Sprite | | BMC | P2.0 | GTP |
| 63 | Holquist / Ripley | Scuderia Bear (USA) | William McKelvy | Abarth-Simca | 1300 | Bialbero | Abarth | GT1.3 | GT I |
| 64 | Norris / Heftler | Crespi Motors (USA) | | Lotus | Elite | | Climax | GT1.3 | GT I |
| 65 | Bolton / Rothschild | Standard Triumph, Inc. (USA) | | Triumph | Spitfire | | Triumph | GT1.3 | GT I |
| 66 | Tullius / Gates | Standard Triumph, Inc. (USA) | | Triumph | Spitfire | | Triumph | GT1.3 | GT I |
| 67 | Barker / Feuerhelm / Rothschild | Standard Triumph, Inc. (USA) | | Triumph | Spitfire | | Triumph | GT1.3 | GT I |
| 68 | Hedges / Mac | British Motor Corp. (GB) | | MG | Midget | | BMC | GT1.3 | GT I |
| 69 | Manley / Sellers | Societe des Automobiles Alpine (F) | | Alpine | A110 | 1100 | Renault | GT1.3 | GT II |
| 70 | Baker / Kirtley / *Mayfield | Fred J. Baker (USA) | | Alpine | A110 | | Renault | GT1.3 | GT I |
| 71 | Hanna / Toland | Howard Hanna (USA) | | René Bonnet | Djet 2 | | Renault | GT1.3 | GT I |
| 81 | Mairesse / Bianchi | Fong Racing Associates (Ferrari Owners Racing Association) (USA) | | Ferrari | 275 P | | Ferrari | P4.0 | GTP |
| 82 | Tannlund / Wagstaff | British Motor Corp. (GB) | | MG | Midget | | BMC | GT1.3 | GT I |
| T | | Porsche Automobile Co. (D) | | Porsche | 904 | GTS | Porsche | GT2.0 | GT II |