| 00 | Ongais / *Follmer / *Field | Interscope Racing (USA) | | Porsche | 911 Carrera RSR Turbo | | Porsche | Sports | |
| 01 | Bergstrom / *Cook | Sports Ltd. Racing (USA) | Bob Bergstrom | Porsche | 911 | S | Porsche | GTU | |
| 02 | Levenson / Rice / Levetto | Al Levenson (USA) | | Chevrolet | Corvette | C2 | Chevrolet | GTO | |
| 03 | Beilcke / *Gebhardt | Bavarian Motors (USA) | | BMW | 2002 | | BMW | GTU | |
| 04 | Kreider / DeMarco | Bill Nelson, Sr. | | Pontiac | Astre | | Pontiac | GTO | |
| 05 | Trueman / Thompson / Yenko | Red Roof Inns, Inc. (USA) | Jim Trueman | Chevrolet | Monza | | Chevrolet | GTO | |
| 07 | Mendez / Cowart / Panaccione | Charles Mendez | | Porsche | 911 | T | Porsche | GTU | |
| 1 | Ickx / Mass / *Barth | Martini Racing Porsche System (D) | | Porsche | 935 | | Porsche | Gr.5 | Div.3/Gr.5 |
| 2 | Hobbs / Peterson / Posey | BMW Motorsport GmbH (USA) | | BMW | 320 | | BMW | GTO | Div.2/Gr.5 |
| 3 | Finotto / Facetti / Camathias | Jolly Club (I) | Martino Finotto | Porsche | 935 | | Porsche | Gr.5 | Div.3/Gr.5 |
| 6 | Johnson / Shaw / Anderson | Levi's Team Highball (USA) | Amos Johnson | AMC | Gremlin | | AMC | GTO | |
| 7 | Arutunoff / Marina / Goellnicht | Hallet Motor Racing Circuit (USA) | Anatoly Arutunoff | Lancia | Stratos | HF | Ferrari | GTU | Div.2/Gr.4 |
| 8 | Jöst / Wollek / Krebs | Porsche Kremer Racing (D) | Kremer Brothers | Porsche | 935 | | Porsche | Gr.5 | Div.3/Gr.5 |
| 9 | Bytzek / Bytzek / Bartling | Bytzek Automotive Design (CDN) | | Porsche | 911 Carrera | RSR | Porsche | GTO | |
| 10 | Speer / Turley / Sahlman | M. L. Speer (USA) | | Porsche | 911 | S | Porsche | GTU | |
| 13 | Fryer / Bostyan / Lowther | University of Pittsburgh (USA) | | AMC | Javelin | | AMC | GTO | |
| 14 | Holbert / Keyser / Ballot-Léna | Dickinson/Holbert Racing (USA) | | Chevrolet | Monza | | Chevrolet | GTO | |
| 17 | Gimondo / *Chitwood | Tim Chitwood (USA) | Tim Chitwood | Chevrolet | Nova | | Chevrolet | GTO | |
| 18 | Swanson / Wolters | Terry Wolters | | Chevrolet | Camaro | | Chevrolet | GTO | |
| 20 | Rondeau / Beltoise / *Holbert | Inaltera Motors (F) | | Inaltera | LM | | Ford | Sports | |
| 21 | Beckers / Lombardi / *Rondeau | Inaltera Motors (F) | | Inaltera | LM | | Ford | Sports | |
| 24 | Frank / Shafer | Executive Industries (USA) | Tom Frank | Porsche | 911 Carrera | RSR | Porsche | GTO | |
| 27 | Mummery / Refenning / Noseda | SVD Automotive (USA) | Jack Refenning | Porsche | 911 | S | Porsche | GTU | |
| 28 | Weiss / Alsup / Gage | Weiss Motor Racing (USA) | Richard Weiss | Porsche | 911 | S | Porsche | GTU | |
| 30 | Dyer / Frisselle | George Dyer (USA) | George Dyer | Porsche | 911 Carrera | RSR 3.0 | Porsche | GTO | Div.2/Gr.4 |
| 33 | Dube / Zitza / Castellano | Ara Dube (USA) | | Porsche | 911 | | Porsche | GTU | |
| 34 | Drolsom / Scott / Bagley | Drolsom Racing (USA) | George Drolsom | Porsche | 911 | S | Porsche | GTU | |
| 36 | Boye / Gillan | Bill Boye | Bill Boye | AMC | Gremlin | | AMC | GTO | |
| 38 | Paul / O'Steen / Hagestad | John Paul (USA) | John Paul | Porsche | 911 Carrera | RSR | Porsche | GTO | |
| 39 | Doran / Barnett / Pelz | Wiley Doran (USA) | Wiley Doran | Chevrolet | Corvette | | Chevrolet | GTO | |
| 40 | Sepelon / Lee / Parker | Robert V. LeMay | | Ford | Mustang | | Ford | GTO | |
| 41 | Jones, Jr. / Faul | Jones Ind. Racing (USA) | Herb Jones, Jr. | Chevrolet | Camaro | II | Chevrolet | GTO | |
| 42 | Hindson / Carney / Davenport | Bob Hindson Racing | Bob Hindson | Porsche | 911 | S | Porsche | GTU | |
| 43 | Haywood / Graves / Helmick | Ecurie Escargot (USA) | Dave Helmick | Porsche | 911 Carrera | RSR | Porsche | GTO | Div.2/Gr.4 |
| 46 | DeNarvaez / Naon / Freyre | Mauricio de Narvaez (CO) | Mauricio DeNarvaez | Porsche | 911 Carrera | RSR | Porsche | GTO | |
| 47 | Fitzpatrick / Miller / Miller | KWM Racing (USA) | Kenper Miller | BMW | 3.5 CSL | | BMW | GTO | Div.3/Gr.5 |
| 48 | Sereix / Carusso / Donaldson | Autodyne (USA) | John Carusso | Chevrolet | Corvette | C3 | Chevrolet | GTO | |
| 49 | Fillingham / Williamson / Jones | Fillingham Racing | Sam Fillingham | Chevrolet | Corvette | | Chevrolet | GTO | |
| 50 | Waugh / Rulon-Miller / Punch | Tom Waugh | | AMC | Hornet | | | GTO | |
| 51 | Kirby / Hotchkis / *Aase | Kirby Hitchcock Racing (USA) | Bob Kirby/Hitchcock | Porsche | 914 | /6 | Porsche | GTU | |
| 55 | Thompkins / Heinz / Mann | Rick Thompkins (USA) | | Chevrolet | Corvette | | Chevrolet | GTO | |
| 58 | Febles / Gonzalez / Cruz | Diego Febles Racing (PR) | Diego Febles | Porsche | 911 Carrera | RSR | Porsche | GTO | |
| 60 | Bond / Tilton / Thomas | R & R Racing | Rusty Bond/Ren Tilton | Porsche | 911 | S | Porsche | GTU | |
| 61 | Gregg / Busby | Brumos Racing (USA) | Jim Busby | Porsche | 934 | | Porsche | GTO | |
| 63 | Field / Woodner / *Holmes / *Ongais | Interscope Racing (USA) | Ted Field | Porsche | 911 Carrera | RSR 3.0 | Porsche | GTO | |
| 64 | Forbes-Robinson / Newman / Minter | Ramsey Ferrari/Modena (USA) | Otto Zipper | Ferrari | 365 GTB/4 | | Ferrari | GTO | Div.3/Gr.5 |
| 65 | Carradine / Morton / Woods | Ramsey Ferrari/Modena | David Carradine | Ferrari | 365 GTB/4 | | Ferrari | GTO | |
| 66 | Adamowicz / Cannon / Barbour | Ramsey Ferrari/Modena (USA) | | Ferrari | 365 GTB/4 | | Ferrari | GTO | Div.3/Gr.5 |
| 70 | Gang / Gonzalez / Duke / *Papke | Michael Callas (USA) | Michael Callas | Porsche | 911 Carrera | RSR | Porsche | GTO | |
| 71 | Higgins / Mead / White | The Foreign Exchange | | Porsche | 911 | S | Porsche | GTU | |
| 72 | Arnold / Thompson / Hagan | Bill Arnold Racing (USA) | | Chevrolet | Corvette | | Chevrolet | GTO | |
| 73 | Howey / Crabtree / Koch | Howey Farms | | Chevrolet | Corvette | C2 | Chevrolet | GTO | |
| 77 | Greenwood / Mancuso / Cargill / Heinz | Mancuso Chevrolet (USA) | Rick Mancuso | Chevrolet | Corvette | C3 | Chevrolet | GTO | |
| 78 | Headley / Feinstein / *Panzarella | Babe's Garage (USA) | Babe Headley | Chevrolet | Corvette | C3 | Chevrolet | GTO | |
| 79 | Callas / Jolly / Laffeach / Papke | Michael Callas (USA) | Michael Callas | Porsche | 911 Carrera | RSR 3.0 | Porsche | GTO | |
| 80 | Solomone / Lang / *Fyhrie | Carmon Solomone | | Chevrolet | Camaro | | Chevrolet | GTO | |
| 84 | Boykin / Henderson / *Canada | Lenton B. McGill (USA) | C. C. Canada | Chevrolet | Camaro | I | Chevrolet | GTO | |
| 96 | Felton / Cason / Reeve | Clay Young | | Chevrolet | Camaro | | Chevrolet | GTO | |
| 98 | Tolman / *Brockman / *Sommers | Ralph Tolman | | Lotus | Europa | | | GTU | |
| 99 | Currin / Hoskins / Knab | Phil Currin (USA) | Cliff Gottlob | Chevrolet | Corvette | | Chevrolet | GTO | |