| 0 | Field / Ongais | Interscope Racing (USA) | Ted Field | Porsche | 935 | K3/80 | Porsche | GTX |
| 00 | Ongais / Field | Interscope Racing (USA) | Ted Field | Porsche | 935 | /77A | Porsche | GTX |
| 01 | Follmer / McKitterick | Roy Woods (USA) | Roy Woods | Chevrolet | Monza | Turbo | Chevrolet | GTX |
| 03 | Frank / Schramm | Toyota Village (USA) | Werner Frank | Porsche | 934 | | Porsche | GTO |
| 04 | Ward / Snow | David Ward | | Chevrolet | Corvette | | Chevrolet | GTO |
| 05 | Akin / Woods / Kent-Cooke | Racing Associates (USA) | | Porsche | 935 | K3 | Porsche | GTX |
| 06 | Fassler / Mullen | Fassler - Mullen Racing (USA) | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 09 | Paul / *Henn | John Paul Racing (USA) | Preston Henn | Porsche | 935 | K3 | Porsche | GTX |
| 2 | Tachi / Sharp / Satou | Dome/Tom's (J) | | Dome | Celica Turbo | | Toyota | GTX |
| 3 | Busby / *Brabham | Jim Busby Industries (USA) | Jim Busby | BMW | March M1 | | Chevrolet | GTX |
| 5 | Mendez / Redman | Racing Associates (USA) | Charles Mendez | Porsche | 935 | K3 | Porsche | GTX |
| 6 | Fitzpatrick / Barbour | Dick Barbour Racing (USA) | Dick Barbour | Porsche | 935 | K3/80 | Porsche | GTX |
| 7 | Bohren / Yorino | Racing Beat | | Mazda | RX-7 | | Mazda | GTU |
| 8 | Arutunoff / Marina | Anatoly Arutunoff (USA) | Anatoly Arutunoff | Lancia | Stratos | HF | Ferrari | GTU |
| 9 | Rahal / Garretson | Dick Barbour Racing (USA) | Dick Barbour | Porsche | 935 | K3 | Porsche | GTX |
| 10 | Raub / Oleyar | Oftedahl Trucking (USA) | Gordon Oftedahl | Chevrolet | Camaro | II | Chevrolet | GTO |
| 11 | Nylander / Nylander | Race Tech | | Porsche | 911 | | Porsche | GTU |
| 13 | Townsend / Jenner | Andial Racing (USA) | Randolph Townsend | Porsche | 935 | | Porsche | GTX |
| 17 | Kline / *Downing | Racing Beat | | Mazda | RX-7 | | Mazda | GTU |
| 18 | Cord / Adam | Chris Cord (USA) | | Chevrolet | Monza | | Chevrolet | GTX |
| 19 | Nardi / Nardi | Nardi Motors | | Porsche | 911 | | Porsche | GTO |
| 20 | Cord / Adams | Chris Cord Racing (USA) | | Chevrolet | Monza | | Chevrolet | GTX |
| 22 | Bruckmann / Goodell | Volker Bruckmann | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 23 | Carney / Davenport | Frank L. Carney (USA) | Frank Carney | Datsun | 280ZX | | Datsun | GTU |
| 24 | Nunnally / Goodspeed | Group 24 Ltd. | | Porsche | 924 | | Porsche | GTU |
| 25 | Cowart / *Miller | Red Lobster Racing (USA) | | BMW | M1 | | BMW | GTX |
| 27 | Morenfeld / Pontier / *Jones | Joel Morenfeld | | Porsche | 911 | SC | Porsche | GTU |
| 28 | Zulkowski / *Johnson | Metal Craft Racing (USA) | | Porsche | 914 | /6 | Porsche | GTU |
| 30 | Moretti / Minter | Electrodyne (I) | Giampiero Moretti | Porsche | 935 | J | Porsche | GTX |
| 31 | Overstreet / Lanfre / Marx | RSR Associates (USA) | Tom Alan Marx | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 34 | Richie / Miller / Ryan | Westport Racing (USA) | | Porsche | 911 | | Porsche | GTU |
| 37 | Espinosa / Cortes | Botero Racing (CO) | Luis Botero | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 39 | Barker / LaCava | Gregg La Cava (USA) | | Porsche | 911 | | Porsche | GTU |
| 40 | Anderson / Sloma | Joel Anderson (USA) | Joel Anderson | Datsun | 240Z | | Datsun | GTU |
| 41 | Craine / James | B. C. Auto Body (USA) | Bill Craine | Chevrolet | Corvette | C3 | Chevrolet | GTO |
| 42 | Shaw / Northam | International Racing Systems | William L. Shaw | Honda | Civic | Turbo | Honda | GTX |
| 44 | Tullius / Adam | Jaguar - Rover - Triumph/Quaker State (USA) | | Triumph | TR8 | | Rover | GTO |
| 45 | Ratcliff / Koll | R. F. Ratcliff (USA) | | Porsche | 914 | /6 | Porsche | GTU |
| 46 | DeNarvaez / Naon | DeNarvaez Enterprises (CO) | Mauricio DeNarvaez | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 47 | Frisselle / Katayama | Brad Frisselle Racing (USA) | Brad Frisselle | Mazda | RX-7 | | Mazda | GTU |
| 48 | Carusso / Currin | Dynasales (USA) | John Carusso | Chevrolet | Corvette | C3 | Chevrolet | GTO |
| 49 | Copeman / Speer | Tortilla Flats Racing (USA) | Bob Copeman | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 54 | Garcia / Herman / *Vadia | Montura Racing (USA) | Tony Garcia | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 55 | Meister / Morton | Andial Racing/Meister Homes (USA) | Howard Meister | Porsche | 935 | M16 | Porsche | GTX |
| 56 | Borlase / Kravig / Hammond | Rick Borlase | | Porsche | 911 Carrera | | Porsche | GTO |
| 57 | Haas / Smith-Haas / Scott | Personalized Porsche (USA) | Wayne Baker | Porsche | 914 | /4 | VW | GTU |
| 59 | Gregg / Holbert | Brumos Porsche Audi (USA) | Peter Gregg | Porsche | 935 | /79 | Porsche | GTX |
| 61 | Tom Waugh | Doell Associates | | Plymouth | Volare | | Plymouth | GTX |
| 62 | Koll / Cook | Koll Motor Sports (USA) | | Porsche | 911 | | Porsche | GTU |
| 64 | Aase / *Johnson | Alan Johnson Racing (USA) | | Porsche | 911 | | Porsche | GTU |
| 66 | Crevier / Halsmer | Crevier Imports (USA) | Joe Crevier | Ferrari | 365 GTB/4 | | Ferrari | GTO |
| 68 | Mendez / Rodriguez | Hector Huerta Racing (DR) | Hector Huerta | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 69 | Duffy / Ferguson | Crevier Imports | Joe Crevier | Ferrari | 512 BB | | Ferrari | GTX |
| 71 | Long / Roberts | W. D. Long | | Datsun | 200SX | | Datsun | GTU |
| 73 | Demele / Goodspeed / *Bramante | Jerry Demele Racing (USA) | Jerry Demele | Porsche | 911 | | Porsche | GTU |
| 74 | Brallier / Mock | Round Table Racing (USA) | | Chevrolet | Corvette | | Chevrolet | GTO |
| 76 | Chamberlain / Chamberlain | Arrow Heating Co. (USA) | | Chevrolet | Corvette | C3 | Chevrolet | GTX |
| 77 | Mandeville / Fisher | Mandeville Racing (USA) | Roger Mandeville | Mazda | RX-7 | | Mazda | GTU |
| 79 | Bergstrom / *Bedard | Sports Ltd. Racing (USA) | Bob Bergstrom | Mazda | RX-7 | | Mazda | GTU |
| 81 | Dietrich / Winters / Cook | Trinity Racing | | Mazda | RX-7 | | Mazda | GTU |
| 82 | Casey / Knoop | Trinity Racing (USA) | | Mazda | RX-7 | | Mazda | GTU |
| 83 | Devendorf / Adamowicz | Electramotive (USA) | | Datsun | 280ZX | | Datsun | GTU |
| 85 | Bienvenue / Rowe | Fifth Essence Racing | Jacques Bienvenue | Chevrolet | Corvette | | Chevrolet | GTX |
| 86 | Leven / Haywood | Bayside Disposal (USA) | | Porsche | 935 | /77A | Porsche | GTX |
| 86T | | Bayside Disposal (USA) | Bruce Leven | Porsche | 935 | | Porsche | GTX |
| 88 | Maashoff / Michaelson / Korpiel | Barry Maashoff | | Porsche | 911 | | Porsche | GTO |
| 89 | Soto / Honegger | Hector Huerta Racing (YV) | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 90 | Johnson / *Malloy / *McDonough | Edward J. Johnson | | Datsun | 280ZX | | Datsun | GTO |
| 91 | Whittington / Whittington | Whittington Brothers Racing (USA) | Whittington Brothers | Porsche | 935 | K3 | Porsche | GTX |
| 93 | Whittington / Whittington | Whittington Bros. (USA) | | Porsche | 935 | K3 | Porsche | GTX |
| 94 | Whittington / Chandler / *Whittington / *Brolin | Whittington Bros. (USA) | Whittington Brothers | Porsche | 935 | /79 | Porsche | GTX |
| 95 | Stiff / Posey | NTS Racing | | Datsun | 240Z | | Datsun | GTU |
| 96 | Alderman / Earl | NTS Racing | | Datsun | 240Z | | Datsun | GTU |