| 00 | Showket / *Schroeder / *Currin | Full-Time Racing (USA) | | Dodge | Daytona | | Dodge | GTU |
| 01 | Bell / Morgan / Los | AT&T Spice Engineering | | Spice | SE87L | | Pontiac | Lights |
| 03 | McCall / Dallenbach / Jones / Baldwin | Skoal Bandit Racing | | Chevrolet | Camaro | | Chevrolet | GTO |
| 04 | Auberlen / Gang / Eisenlohr / Auberlen | SP Racing (USA) | | Porsche | 911 Carrera | | Porsche | GTU |
| 05 | Taylor / Harrower / Flux / Dickens | A.D.A. Engineering (GB) | | ADA | 03 | | Ford | GTP |
| 06 | Nelson / Brown / Hagen / *Marlin | Brown Racing (USA) | | Tiga | GT286 | | Buick | Lights |
| 08 | Burgner / Romano / Colom / Green / *Cory | Simms-Romano Enterprises (USA) | | Mazda | RX-7 | | Mazda | GTU |
| 09 | Durst / Brockman / Earl / Belcher | Jiffy Lube Firebird | | Spice | SE86CL | | Pontiac | GTP |
| 1 | Foyt / Unser, Jr. / Forbes-Robinson | Copenhagen-A. J. Foyt Racing (USA) | | Porsche | 962 | | Porsche | GTP |
| 2 | Pickett / Jones / Riggins | Polyvoltac/Protofab (USA) | Jack Roush | Chevrolet | Corvette C4 | | Chevrolet | GTO |
| 3 | Brancatelli / Larrauri / Sigala | Brun Motorsports-Torno (CH) | Walter Brun | Porsche | 962 | | Porsche | GTP |
| 4 | Miller / Ludemann / Schubot | S & L Racing (USA) | | Spice | SE88P | | Buick | Lights |
| 5 | Archer / Mead / Adam | Polyvoltac/Protofab (USA) | | Chevrolet | Corvette C4 | | Chevrolet | GTO |
| 6 | Miller / Akin / Gentilozzi / *Halsmer / *Pruett | Roush Racing (USA) | Jack Roush | Merkur | XR4Ti | | Ford | GTO |
| 7 | Jenner / Goodyear / Luyendyk / Gloy / Fish / Schwietz | Tom Milner Racing (USA) | | Ford | Mustang Probe | | Ford | GTP |
| 8 | Mead / McAdam / McDonough | Fabcar American Racing (USA) | | Fabcar | GTP | | Chevrolet | GTP |
| 9 | Simpson / Hessert / Loring | Essex Racing Service (USA) | | Tiga | GT286 | | Chevrolet | Lights |
| 10 | Adams / Hotchkis, Jr. / Hotchkis | Hotchkis Racing Inc. (USA) | John Hotchkis | Porsche | 962 | | Porsche | GTP |
| 11 | Pruett / Miller / Akin / Halsmer | Roush Racing (USA) | Jack Roush | Merkur | XR4Ti | | Ford | GTO |
| 12 | Allison / Allison / Danielson | Bobby Allison Racing | | Buick | Somerset | | Buick | GTO |
| 14 | Holbert / Robinson / Bell | Holbert Racing (USA) | | Porsche | 962 | | Porsche | GTP |
| 15 | Rothbarth / Jourdain / Jourdain / Stevens | Kalagian Racing | | Porsche | 962 | | Porsche | GTP |
| 16 | Cobb / Weaver / Dyson / Schuppan | Dyson Racing (USA) | Rob Dyson | Porsche | 962 | | Porsche | GTP |
| 17 | Bacon / Reed / Hogdal | Al Bacon Performance (USA) | Al Bacon | Mazda | RX-7 | | Mazda | GTU |
| 18 | Beasley / Volk / Lewis | Jack Lewis Enterprises (USA) | | Porsche | 911 Carrera | RSR | Porsche | GTO |
| 19 | McKay / Jacobson / Brown | Essex Racing Service (USA) | | Tiga | GT286 | | Mazda | Lights |
| 20 | McDill / Juckette / McDill | Data-Gas | Bill McDill | March | 84G | | Pontiac | GTP |
| 21 | O'Neill / Wood / Rocha | John Wood Racing | | Alba | AR5 | | Buick | GTP |
| 22 | Martin / St. James / Gregg / Halsmer | Roush Racing (USA) | | Mercury | Capri | | Ford | GTO |
| 23 | Petrilak / McDaniel / MacInnes / *Ministri | Motion Promotion | | Argo | JM16 | | Buick | Lights |
| 24 | McComb / Briody / Nagel | Briody Racing (USA) | | March | 84G | | Buick | GTP |
| 27 | Cowart / Fowells / Mummery / Meyer | MSB Racing (USA) | | Argo | JM19 | | Mazda | Lights |
| 28 | Church / Urrutia / Generotti / Vitolo / *Boody | Florida Fixtures (USA) | Guy W. Church | Mazda | RX-7 | | Mazda | GTU |
| 29 | Kimbrough / Overbagh / Gennone / Kicak / *Rose / *Stills | Overbagh Motor Racing (USA) | Hoyt Overbagh | Chevrolet | Camaro | III | Chevrolet | GTO |
| 30 | Roe / Moretti / *Barilla | Buick Momo March (I) | | March | 86G | | Buick | GTP |
| 31 | Phillips / Andretti / Roe | Buick Momo March (I) | | March | 86G | | Buick | GTP |
| 33 | Petery / Delano / Carter / *Halsmer | Roush Racing (USA) | Jack Roush | Mercury | Capri | | Ford | GTO |
| 34 | Collins / Carpenter / Struble | Ray Hendricks | | Ukina | | | Jaguar | Lights |
| 35 | Gonzalez / Winfree / Villa / Schneider | Diman Racing | | Royale | RP40 | | Porsche | Lights |
| 36 | Grooms / Bagley / Fergus / Jellinek | Erie Scientific | | Argo | JM16 | | Mazda | Lights |
| 38 | Mandeville / Marsh / Marsh | Mandeville Auto Tech (USA) | Roger Mandeville | Mazda | RX-7 | | Mazda | GTO |
| 39 | Hebert / Reisman / Strasser | HRG Associates (USA) | | Pontiac | Firebird | | Pontiac | GTO |
| 40 | Pallavicini / Guatamacchi / Bieri / Johnson | Gaston Andrey Racing | | Alba | AR2 | | Ferrari | Lights |
| 42 | Newsum / Cherry / McAdam / Higgins | Lamas Motor Racing | | Fabcar | CL | | Porsche | Lights |
| 44 | Tullius / Ganz / Haywood | Group 44 (USA) | | Jaguar | XJR-7 | | Jaguar | GTP |
| 45 | Keck / Kennedy / Wonzer / Cameron | K & P Racing (USA) | Karl Keck | Chevrolet | Corvette C4 | | Chevrolet | GTO |
| 47 | Oakley / Mnich / Mills / *Meyer | Cumberland Valley Racing (USA) | Chaunce Wallace | Mazda | RX-7 | | Mazda | GTU |
| 48 | Monk / King / Lamas / *Jones / *Young | Lamas Motor Racing | | Fabcar | CL | | Porsche | Lights |
| 51 | Richard / Azcona / Copeman | Mardi Gras Racing (USA) | Heinz Peters | Porsche | 911 Carrera | RSR | Porsche | GTU |
| 53 | Evans / Broomall / Ullom / Hanneman | Team Shelby (USA) | Carroll Shelby | Dodge | Daytona | | Dodge | GTU |
| 55 | Visger / Lewis / Woodner | Huffaker Racing (USA) | | Spice | SE86CL | | Pontiac | Lights |
| 56 | Durkheimer / Shelton / Torres / Northam | Escort Porsche (USA) | Karl Durkheimer | Porsche | 911 Carrera | | Porsche | GTU |
| 58 | Green / Hamilton / Bean / Wonzer / *Uria / *Cameron | Gary Wonzer (USA) | Gary Wonzer | Lola | T616 | | Mazda | Lights |
| 60 | Brundle / Boesel / Nielsen | Castrol/Jaguar Racing (GB) | | Jaguar | XJR-9 | D | Jaguar | GTP |
| 61 | Jones / Sullivan / Lammers | Castrol/Jaguar Racing (GB) | | Jaguar | XJR-9 | D | Jaguar | GTP |
| 63 | Katz / Matsushita / Downing | Downing/Atlanta (USA) | | Argo | JM19 | | Mazda | Lights |
| 65 | English / Thompson / Felton / Laws | Gary English (USA) | | Royale | RP40 | | Buick | Lights |
| 66 | Cheever / Watson / Dumfries | Castrol/Jaguar Racing (GB) | | Jaguar | XJR-9 | D | Jaguar | GTP |
| 67 | Wollek / Baldi / Redman | Uniroyal Goodrich (USA) | Jim Busby | Porsche | 962 | | Porsche | GTP |
| 68 | Walker / Smith / Lagasse | Greg Walker Racing | | Chevrolet | Corvette | | Chevrolet | GTO |
| 71 | Johnson / Shaw / Lazier | Team Highball (USA) | Amos Johnson | Mazda | RX-7 | | Mazda | GTU |
| 72 | Allison / Hynes / Ashmore | Roy Baker (GB) | Roy Baker | Tiga | GC286 | | Ford | GTP |
| 75 | Kendall / Unser / Frank / *Johnson | CCR (USA) | Clayton Cunningham | Mazda | RX-7 | | Mazda | GTU |
| 76 | Morton / Jones / Jones / *Binks | CCR (USA) | Clayton Cunningham | Mazda | RX-7 | | Mazda | GTO |
| 77 | Luyendyk / Gloy / Pumpelly | Tom Milner Racing (USA) | | Ford | Mustang Probe | | Ford | GTP |
| 79 | McKitterick / Koll / Winters / Ballot-Léna / Hytten | Winters/Whitehall (USA) | | Spice | SE87L | | Pontiac | Lights |
| 80 | Finotto / Silva / Daccò | Gaston Andrey Racing (USA) | | Alba | AR6 | | Ferrari | Lights |
| 81 | Bupp / Boxstrom / Painter / Church | Sentry Bank Equipment (USA) | Ken Bupp | Chevrolet | Camaro | | Chevrolet | GTO |
| 82 | Greer / Mees / Finger | Apenn Inn (USA) | Dick Greer | Mazda | RX-7 | | Mazda | GTU |
| 84 | Wesel / Rubright / Jenkins | Car Enterprises | | Chevrolet | Camaro | | Chevrolet | GTO |
| 86 | Stuck / Ludwig / van der Merwe / *Leven | Bayside Motorsport (USA) | Bruce Leven | Porsche | 962 | | Porsche | GTP |
| 88 | Johnson / Strait / Nicol | Transact, Inc. | | Argo | JM19 | B | Ferrari | Lights |
| 89 | Uria / Refenning / Figaro / Scott | 901 Racing (USA) | | Porsche | 911 Carrera | RSR | Porsche | GTU |
| 92 | Zwiren / Montgomery / Puleo / *Brosnaham / *Pio Costa | Puleo Racing | | Pontiac | Firebird | | Pontiac | GTO |
| 94 | Bond / *Tisdelle / *Van Every | Ash Tisdelle (USA) | | Chevrolet | Camaro | | Chevrolet | GTO |
| 95 | Leitzinger / Kurtz / Leitzinger | Leitzinger Racing (USA) | Bob Leitzinger | Nissan | 300ZX | | Nissan | GTU |
| 96 | Mahre / Mundas / *Mahre / *Bender | URD Junior Team | | URD | C82 | | BMW | GTP |
| 97 | Ballot-Léna / Ricci / Iacobelli | Winters/Whitehall (USA) | | Spice | SE88P | | Pontiac | Lights |
| 98 | Cord / Aase / Millen | All-American Racers (USA) | Dan Gurney | Toyota | Celica | Turbo | Toyota | GTO |
| 99 | Ribbs / Moran / Fangio II | All-American Racers (USA) | Dan Gurney | Toyota | Celica | Turbo | Toyota | GTO |