| 0 | Jelinski / Ricci / Wollek | Joest Racing (D) | | Porsche | 962 | C | Porsche | GTP |
| 00 | Showket / Hanneman | Full Time Racing (USA) | | Dodge | Daytona | | Dodge | GTU |
| 03 | Jones / McCall | Skoal Bandit Racing | | Chevrolet | Camaro | III | Chevrolet | GTO |
| 05 | Hendrick / *Gallant | Ken Hendrick Racing (USA) | Art Hendrick | Oldsmobile | Toronado | | Buick | GTO |
| 09 | Durst / Brockman / Cochran / *Belcher | Ball Bros. Racing | | Spice | SE88P | | Buick | GTP |
| 2 | Jones / Jones / Andison | Powell Equipment | | Chevrolet | Corvette | | Chevrolet | GTO |
| 4 | Schubot / Blackaller / Ludemann | S & L Racing (USA) | | Spice | SE88P | | Buick | Lights |
| 4T | Schubot / Ludemann | S & L Racing (USA) | | Spice | SE88P | | Buick | Lights |
| 7 | Negron / Soldevilla / Gordillo | Juan Carlos Negron (PR) | | Mazda | RX-7 | | Mazda | GTU |
| 9 | Morgan / Hessert | Essex Racing (USA) | | Spice | SE88P | | Buick | Lights |
| 10 | Adams / Hotchkis / Hotchkis, Jr. | Hotchkis Racing (USA) | John Hotchkis | Porsche | 962 | | Porsche | GTP |
| 11 | Dallenbach, Jr. / Schroeder | Roush Racing (USA) | Jack Roush | Mercury | Cougar | VII XR-7 | Ford | GTO |
| 12 | Lopez / Rocca / Bobeda | Carlos Bobeda Racing (USA) | Carlos Pobeda | Tiga | GT286 | | Mazda | Lights |
| 16 | Halsmer / Earl | Roush Racing (USA) | Jack Roush | Mercury | Cougar | VII XR-7 | Ford | GTO |
| 17 | Bacon / Reed | Al Bacon Perf (USA) | Al Bacon | Mazda | RX-7 | | Mazda | GTU |
| 18 | Bupp / Peters | Ken Bupp (USA) | | Chevrolet | Camaro | | Chevrolet | GTO |
| 19 | Smith / Dow / Shalett | Essex Racing (USA) | | Tiga | GT288 | | Buick | Lights |
| 22 | Church / Generotti / D'Agostino | Guy Church (USA) | Guy W. Church | Mazda | RX-7 | | Mazda | GTU |
| 23 | Raul Garcia | Raul Garcia (USA) | Raul Garcia | Pontiac | Firebird | | Pontiac | GTO |
| 25 | O'Neill / Shelton / *Courtney / *Wilkie | Brent O'Neill (USA) | Brent O'Neill | Argo | JM19 | | Buick | Lights |
| 30 | Moretti / Sigala / Roe / Bell | Momo/Gebhardt Racing (D) | | Porsche | 962 | | Porsche | GTP |
| 30T | Moretti / Sigala | Momo/Gebhardt Racing (D) | | Porsche | 962 | C | Porsche | GTP |
| 33 | Los / Kline / *Quester | Spice Engineering USA (GB) | | Spice | SE89P | Pontiac Firebird GTP | Pontiac | GTP |
| 38 | Mandeville / Marsh / *Drummond | Mandeville Auto Tech (USA) | Roger Mandeville | Mazda | RX-7 | | Mazda | GTO |
| 39 | Gunn / *Mead / *Belcher | Phoenix Race Cars | | Phoenix | JG2 | | Chevrolet | GTP |
| 40 | Finotto / Guatamacchi / Bieri | Bieri Racing (CDN) | Uli Bieri | Tiga | GT286 | | Ferrari | Lights |
| 42 | Taylor / Montgomery | Bobs Speed Products | | Pontiac | Firebird | | Pontiac | GTO |
| 43 | Monk / Lamas / Higgins / Mead | John Higgins | | Fabcar | CL | | Porsche | Lights |
| 44 | Morgan / Opie / Morgan / Bair | Thomas Sapp | | Chevrolet | Corvette C4 | | Chevrolet | GTO |
| 45 | Slater / Brady / Dupont | Charles Slater (USA) | | Porsche | 911 | | Porsche | GTU |
| 45T | Lesnett / Slater / Brady / Dupont | Charles Slater | | Porsche | 911 | | Porsche | GTU |
| 46 | Urrutia / *Whipp / *Smith | Team Gulfwind | | Chevrolet | Camaro | | Chevrolet | GTO |
| 47 | de Lesseps / Sereix / Wallace / Regout | Lion Rampant Racing | Chaunce Wallace | Chevrolet | Camaro | | Chevrolet | GTO |
| 47T | de Lesseps / Sereix / Wallace / Regout | Chaunce Wallace | Chaunce Wallace | Chevrolet | Camaro | | Chevrolet | GTO |
| 48 | Graham / Russell / Crouch | Red Line Racing | | BMW | 325i | | BMW | GTU |
| 50 | Bartling / Brezinka / Hochreuter | Fritz Hochreuter (CDN) | | Porsche | 911 | | Porsche | GTU |
| 53 | McDill / McDill | Bill McDill | | Chevrolet | Camaro | | Chevrolet | GTO |
| 55 | Lesnett / Marvin | Huffaker Racing (USA) | | Spice | SE86CL | | Pontiac | Lights |
| 57 | Kryder / Gimble / Del Vecchio | Kryderacing (USA) | | Nissan | 300ZX | | Nissan | GTU |
| 58 | Bean / *Northam / *Wonzer / *Westcott / *Dow | Gary Wonzer Racing (USA) | Gary Wonzer | Lola | T616 | | Mazda | Lights |
| 60 | Jones / Lammers | Castrol Jaguar Racing (GB) | | Jaguar | XJR-9 | D | Jaguar | GTP |
| 61 | Nielsen / Cobb | Castrol Jaguar Racing (GB) | | Jaguar | XJR-9 | D | Jaguar | GTP |
| 62 | Job / Kraft / Bond | Alex Job Racing (USA) | | Porsche | 911 | | Porsche | GTU |
| 63 | Downing / O'Steen / Katz | Downing/Atlanta (USA) | | Argo | JM19 | | Mazda | Lights |
| 66 | | Castrol Jaguar Racing (GB) | | Jaguar | XJR-9 | | Jaguar | GTP |
| 67 | Wollek / Bell / Andretti | Busby Racing (USA) | Jim Busby | Porsche | 962 | | Porsche | GTP |
| 68 | Mendez / Gonzalez / Ferrer | Luis Mendez (DR) | | Porsche | 911 Carrera | RSR | Porsche | GTU |
| 71 | Johnson / Shaw / Lewis / *Robson | Team Highball (USA) | Amos Johnson | Mazda | RX-7 | | Mazda | GTU |
| 72 | Kjoller / Mooney / Volk | Jay Kjoller (USA) | Jay Kjoller | Porsche | 911 | | Porsche | GTU |
| 74 | Robinson / Kendall / Unser | Huffaker Racing | | Pontiac | Fiero | | Pontiac | GTU |
| 75 | Morton / Millen | Cunningham Racing (USA) | Clayton Cunningham | Nissan | 300ZX | Turbo | Nissan | GTO |
| 82 | Greer / Mees / Finger | Dick Greer Racing (USA) | | Mazda | RX-7 | | Mazda | GTU |
| 83 | Robinson / Brabham / Luyendyk | Electramotive Engineering (USA) | | Nissan | GTP ZX-T | | Nissan | GTP |
| 84 | Luyendyk / *Robinson / *Brabham | Electramotive Engineering (USA) | | Nissan | GTP ZX-T | | Nissan | GTP |
| 86 | Weaver / Dobson | Bayside Racing/Bruce Leven (USA) | | Porsche | 962 | | Porsche | GTP |
| 87 | Stewart / Cortez / *Alkazian | Overton Autosport | | Mazda | RX-7 | | Mazda | GTU |
| 89 | Uria / Refenning / Baker | 901 Racing (USA) | | Porsche | 911 Carrera | RSR | Porsche | GTU |
| 90 | Delano / Petery / Carter | Road Circuit Technology | | Mercury | Capri | | Ford | GTO |
| 95 | Leitzinger / Leitzinger / Kurtz | Leitzinger Racing (USA) | | Nissan | 240SX | | Nissan | GTU |
| 98 | Cord / Bren / Olson | All American Racers (USA) | | Toyota | 88C | | Toyota | GTP |
| 99 | Ribbs / Fangio II | All American Racers (USA) | Dan Gurney | Eagle | HF89 | | Toyota | GTP |