| 0 | Field / Ongais | Interscope Racing (USA) | | Porsche | 935 | K3/80 | Porsche | GTP |
| 00 | Field / Ongais | Interscope Racing (USA) | Ted Field | Porsche | 935 | K3/80 | Porsche | GTP |
| 01 | Morton / Klausler | Marketing Corporation (USA) | | Ford | Mustang | | Ford | GTO |
| 02 | Minter / Bauer | Marketing Corporation | | Ford | Mustang | | Ford | GTO |
| 03 | Pallavicini / Crang / Sheldon | Angelo Pallavicini (CH) | Angelo Pallavicini | Porsche | 935 | | Porsche | GTP |
| 05 | Almeida / Soto / Rodriguez | T & R Racing (USA) | Tico Almeida/Rene Rodriguez | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 07 | Buckley / Aschenbrenner / Rutherford | Road Runner Racing (CDN) | | Porsche | 914 | /6 | Porsche | GTU |
| 09 | Henn / Whittington / Lanier | T-Bird Swap Shop (USA) | Preston Henn | Porsche | 935 | K3/80 | Porsche | GTP |
| 2 | Fitzpatrick / *Hobbs | John Fitzpatrick Racing (GB) | John Fitzpatrick | Porsche | 935 | K3/80 | Porsche | GTP |
| 3 | Skiff / Leo | Ned Skiff | | Renault | 12 | | Renault | GTU |
| 4 | Brassfield / Brassfield / Cooper | Oftedahl Racing (USA) | Gordon Oftedahl | Pontiac | Firebird | | Pontiac | GTO |
| 5 | Bell / Siebert / Akin | Bob Akin Motor Racing (USA) | Bob Akin | Porsche | 935 | K3/80 | Porsche | GTP |
| 6 | Wilson / Guthrie / Henn | North American Racing Team (USA) | | Ferrari | 512 BB | /LM | Ferrari | GTP |
| 7 | Kent-Cooke / Adams / Hobbs | Cooke Racing (USA) | Ralph Kent-Cooke | Lola | T600 | | Chevrolet | GTP |
| 8 | Speer / Wolters / Mendez | JLP Racing (USA) | John Paul | Porsche | 935 | JLP-2 | Porsche | GTP |
| 9 | Ratcliff / Clay / McKitterick | Garretson Development (USA) | Bob Garretson | Porsche | 935 | K3/80 | Porsche | GTP |
| 10 | Raub / Brassfield / Shafer | Oftedahl Racing (USA) | | Pontiac | Firebird | | Pontiac | GTO |
| 11 | Aase / *Kendall / *Hotchkis | Kendall Racing (USA) | Charles Kendall | BMW | M1 | | BMW | GTO |
| 15 | Lee / White / Pearce | Tim Lee | | Mercury | Capri | | Ford | GTU |
| 16 | Hinze / Whittington / Whittington / *Henn | T-Bird Swap Shop (USA) | Marty Hinze | Porsche | 935 | K3 | Porsche | GTP |
| 17 | Chitwood / Varde | Tim Chitwood | | Chevrolet | Camaro | | Chevrolet | GTO |
| 18 | Paul, Jr. / Paul | JLP Racing (USA) | John Paul | Porsche | 935 | JLP-3 | Porsche | GTP |
| 19 | Tisdelle / Van Every | Van Every Racing (USA) | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 20 | Jernigan / Boyer / *Smith / *Tumbleston | Fuchs-Whitaker | | Chevrolet | Camaro | | Chevrolet | GTP |
| 21 | Crevier / Fassler / Zeigel | Creviér & Associates (USA) | | BMW | M1 | | BMW | GTO |
| 22 | Frank / Madren | Toyota Village Inc. (USA) | Werner Frank | Porsche | 934 | | Porsche | GTO |
| 23 | Garcia / Fernandez | Superior Racing (USA) | | Chevrolet | Camaro | | Chevrolet | GTP |
| 25 | Cowart / Miller | Red Lobster Racing (USA) | | March | 82G | | BMW | GTP |
| 26 | Roe / Selby | Roe-Selby Racing | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 27 | Fowells / Mummery / Carusso | Scuderia Rosso (USA) | | Mazda | RX-7 | | Mazda | GTU |
| 28 | McVey / Deacon / Smith, Jr. | McVey Racing Enterprises | | Chevrolet | Camaro | | Chevrolet | GTO |
| 29 | Overbagh / *Kirill / *Smith, Jr. | Oberdorfer Research | | Oldsmobile | Starfire | | Oldsmobile | GTO |
| 30 | Case / Harry / Pizzagelli | Case Racing | | Porsche | 911 | | Porsche | GTU |
| 31 | Arutunoff / Marina | Hallet Motor Racing Circuit (USA) | Anatoly Arutunoff | Lancia | Stratos | HF | Ferrari | GTU |
| 34 | Drolsom / Johnson / Davey | Drolsom Racing (USA) | George Drolsom | Porsche | 924 | Carrera GTR | Porsche | GTO |
| 36 | Miller / *Bedard / *Barth | Herman-Miller P. A. | | Porsche | 924 | Carrera GTR | Porsche | GTO |
| 38 | Mandeville / Kline / Johnson | Mandeville Racing Ent. (USA) | Roger Mandeville | Mazda | RX-7 | | Mazda | GTU |
| 39 | Brezinka / Bartling / Hochreuter | R & H Racing (CDN) | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 40 | Gordillo / Villa / Gonzalez | Manuel Villa | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 42 | Wonzer / Bean / Grantham | Gary Wonzer | | Porsche | 911 | S | Porsche | GTU |
| 44 | Hagan / Felton | Stratagraph Inc. (USA) | | Chevrolet | Camaro | | Chevrolet | GTO |
| 45 | McGriff / *Brooks | Stratagraph Inc. | | Chevrolet | Camaro | | Chevrolet | GTP |
| 46 | Rahal / DeNarvaez / Trueman | Garretson Development (USA) | Bob Garretson | March | 82G | | Chevrolet | GTP |
| 47 | Rubino / Davis | Frank Rubino (USA) | | Ferrari | 512 BB | /LM | Ferrari | GTP |
| 48 | Currin / Carusso | Sanyo | | Chevrolet | Corvette | | Chevrolet | GTP |
| 50 | Febles / Ferrer / Soldevilla | Diego Febles Racing (PR) | Diego Febles | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 51 | Pimm / Bohren / Carmean | Red Roof Inns (USA) | | Mazda | RX-7 | | Mazda | GTU |
| 53 | "Fomfor" / Valiente / *Gonzalez | Fomfor Racing El Salvador (ES) | | BMW | 3.0 CSL | | BMW | GTO |
| 54 | Garcia / Naon / Stiff | Montura Racing (USA) | | BMW | M1 | | BMW | GTO |
| 58 | Busby / Bundy / Brolin | Brumos Racing (USA) | | Porsche | 924 | Carrera GTR | Porsche | GTO |
| 60 | Lee / Erikson / *Church | Bob's Speed Products | | AMC | AMX | | | GTO |
| 61 | Goral / Northam / Burt | Paul Goral (USA) | Paul Goral | Porsche | 911 | | Porsche | GTU |
| 63 | Downing / Waugh / Maffucci | Jim Downing (USA) | Jim Downing | Mazda | RX-7 | | Mazda | GTU |
| 65 | Baird / Pumpelly / Mead | Prancing Horse Farm Racing | | Ferrari | 512 BB | /LM | Ferrari | GTP |
| 66 | Dunham / Sereix / *Meyer | Dunham Trucking | | Mazda | RX-7 | | Mazda | GTU |
| 68 | Rynerson / McDonald / McDonald | John Rynerson | | Porsche | 911 | | Porsche | GTU |
| 69 | LaGrow / Boyer / Turner | Kenneth LaGrow | | Chevrolet | Monza | | Chevrolet | GTP |
| 71 | Loving / *Belin | Sunrise Auto Parts | | Chevrolet | Camaro | | Chevrolet | GTO |
| 74 | Taylor / Dassinger / *Taylor | Mark Wagoner (USA) | | Chevron | GTP | | Buick | GTP |
| 75 | Lutz / Panaccione | D & L Performance (USA) | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 77 | Davis / Godfredson / Lloyd | Dudley Davis (USA) | | Porsche | 911 | | Porsche | GTU |
| 78 | Smith / Bitterauf / Flanders | Der Klaus Haus | | Porsche | 911 | | Porsche | GTU |
| 79 | Winters / Overby / Bergstrom | ProMotion/Whitehall (USA) | | Porsche | 924 | Carrera GTR | Porsche | GTO |
| 81 | McDill / Meldeau / Juckette | Meldeau Tire World | | Chevrolet | Camaro | | Chevrolet | GTP |
| 82 | Cook / Mullen | Trinity Racing | | Mazda | RX-7 | | Mazda | GTU |
| 84 | "Jamsal" / Barrientos | Scorpio Racing (ES) | | Porsche | 934 | | Porsche | GTO |
| 86 | Haywood / Holbert / Leven | Bayside Disposal Racing (USA) | Bruce Leven | Porsche | 935 | /80 | Porsche | GTP |
| 87 | Mendez / Sanchez / *Ramirez | R. Sanchez Racing | | Mazda | RX-7 | | Mazda | GTU |
| 88 | Shafer / Shafer / Crookston | Shafer Concrete (USA) | Craig Shafer | Chevrolet | Camaro | | Chevrolet | GTO |
| 93 | Bieri / Zingg / Lausberg / *Silte | Uli Bieri | | Porsche | 911 | | Porsche | GTU |
| 94 | Boand / Anderson / Utt | Bard Boand | | Chevrolet | Corvette Sting Ray | | Chevrolet | GTO |
| 96 | Reed / Langlinais | Bon Temps Racing | Ron Reed & Jim Fisher | Datsun | 240Z | | Datsun | GTU |
| 97 | Cummings / Ayes | The Cummings Marque | | Chevrolet | Monza | | Chevrolet | GTP |