| 1st | 2 | Mario Andretti / Jacky Ickx | Ferrari 312 PB | Ferrari | 2:31.4400 |
| 2nd | 4 | Clay Regazzoni / Brian Redman | Ferrari 312 PB | Ferrari | 2:33.0400 |
| 3rd | 31 | Rolf Stommelen / Peter Revson / Andrea de Adamich | Alfa Romeo T33/TT/3 | Autodelta, S.p.A. | 2:33.8600 |
| 4th | 3 | Ronnie Peterson / Tim Schenken | Ferrari 312 PB | Ferrari | 3:35.3700 |
| 5th | 34 | Andrea de Adamich / Nanni Galli | Alfa Romeo T33/TT/3 | Autodelta, S.p.A. | 2:35.9200 |
| 6th | 32 | Vic Elford / Helmut Marko | Alfa Romeo T33/TT/3 | Autodelta, S.p.A. | 2:37.6100 |
| 7th | 7 | Derek Bell / Gijs van Lennep | Mirage M6 Ford | Gulf Research Racing Company | 2:40.6700 |
| 8th | 12 | Gérard Larrousse / Jo Bonnier / Reine Wisell | Lola T280 Ford | Ecurie Bonnier | 2:41.7800 |
| 9th | 33 | Nino Vaccarella / Toine Hezemans | Alfa Romeo T33/TT/3 | Autodelta, S.p.A. | 3:42.7500 |
| 10th | 25 | Nick Craw / Bill Barber | Chevron B19 Ford | Fred Opert | 2:51.2700 |
| 11th | 39 | Roman Pechmann / Rudy Bartling / Milt Minter | Porsche 910 | R. Brezinka | 2:54.0900 |
| 12th | 52 | Hugh Kleinpeter / Tony Belcher | Chevron B21 Ford | Promotional Advertising Corp. | 2:54.9100 |
| 13th | 23 | Charlie Kemp / Oscar Koveleski | Chevrolet Corvette | Rinzler Motoracing, Inc./Holiday Anns of America | 2:56.3100 |
| 14th | 55 | Roger McCaig / Maurice McCaig | Lola T212 Ford | Roger McCaig Racing | 2:56.5600 |
| 15th | 57 | Dave Heinz / Robert R. Johnson | Chevrolet Corvette | Dana English | 2:58.7100 |
| 16th | 56 | Tom Waugh / Bob Beatty | Lola T212 Ford | Promotional Advertising Corp. | 2:59.0000 |
| 17th | 26 | Rodolfo Junco / Fred van Beuren, Jr. | Chevron B19 Ford | Fred Opert | 3:01.2400 |
| 18th | 1 | David Hobbs / Skip Scott | Ferrari 365 GTB/4 | Kirk F. White Motor Racing Inc. | 3:01.5800 |
| 19th | 21 | Tony Adamowicz / Sam Posey | Ferrari 365 GTB/4 | N.A.R.T. | 3:02.2600 |
| 20th | 54 | Anatoly Arutunoff / Brian Goellnicht | Abarth 2000 SP (SE010) | Automobiles International, Inc. | 3:02.0500 |
| 21st | 50 | Don Yenko / John Cordts | Chevrolet Corvette C3 | John Greenwood Racing | 3:04.8900 |
| 22nd | 8 | Tom Nehl / Jim Fitzgerald | Chevrolet Camaro II | Automotive Engineering Enterprises | 3:04.8900 |
| 23rd | 22 | Luigi Chinetti, Jr. / Bob Grossman | Ferrari 365 GTB/4 | N.A.R.T. | 3:05.6500 |
| 24th | 11 | Tony DeLorenzo / Jerry Thompson | Ford Mustang | Troy Promotions, Inc. | 3:05.7900 |
| 25th | 59 | Peter Gregg / Hurley Haywood | Porsche 911 S | Brumos Porsche Audi Corp. | 3:05.7400 |
| 26th | 48 | John Greenwood / Dick Smothers | Chevrolet Corvette | John Greenwood Racing | 3:06.0400 |
| 27th | 80 | John Elliott / Bill McDill | Chevrolet Camaro I | Preston Hood Chevrolet Inc. | 3:08.2000 |
| 28th | 94 | Bob Mitchell / Bob Christiansen | Chevrolet Camaro I | Bolus & Snopes, Ltd. | 3:08.5900 |
| 29th | 27 | Robert Kirby / John Hotchkis | Porsche 914/6 | Bozzani Porsche Audi, Inc. | 3:08.8000 |
| 30th | 97 | Roberto Quintanilla / Jose Martinez | Chevrolet Camaro I | Robeto Quintanilla Jr. | 3:09.0000 |
| 31st | 16 | Michael Keyser / Jürgen Barth | Porsche 911 S | Toad Hall Racing | 3:09.9300 |
| 32nd | 63 | Sepp Greger / Arthur Blank | Porsche 910 | Josef Greger | 3:10.1300 |
| 33rd | 61 | Jim Locke / Bob Bailey | Porsche 911 S | James N. Locke | 3:10.7700 |
| 34th | 24 | John Buffum / John Fitzpatrick | Ford Escort RS 1600 | Libra International Racing | 3:13.1100 |
| 35th | 68 | Robert Stoddard / Joe Hines, Jr. / Frank Harmstad | Porsche 914/6 | H&S Imports Racing | 3:13.8600 |
| 36th | 28 | Erwin Kremer / Günther Huber / Juan Carlos Bolanos | Porsche 911 S | Porsche Kremer Racing Team | 3:14.0000 |
| 37th | 74 | Merv Rosen / Jerry Schaub | Porsche 906 | Carousel Porsche Audi, Inc. | 3:14.2000 |
| 38th | 70 | Lee McDonald / Bert Everett | Porsche 914/6 | Lee McDonald-Algar Porsche Audi, Inc. | 3:14.4700 |
| 39th | 37 | Gary Belcher / Jef Stevens | Chevrolet Camaro | Gary Belcher | 3:14.4900 |
| 40th | 38 | Bob Fisher / Bruce Ponder | Chevron B16 Ford | Hobby Car Enterprises | 3:16.5000 |
| 41st | 43 | Luis Sereix / Javier Garcia | Chevrolet Camaro II | Garcia Racing | 3:17.0000 |
| 42nd | 17 | Vince Gimondo / Billy Dingman | Chevrolet Camaro | Takondo Racing | 3:17.2900 |
| 43rd | 44 | Manuel Garcia / Robert Cao | Chevrolet Nova | Larrauri Racing | 3:17.4200 |
| 44th | 47 | Bob Gray / Terry Keller | Chevrolet Corvette | Sebring Racing Inc. | 3:17.6900 |
| 45th | 10 | John Tremblay / David Ellis-Brown | Chevrolet Camaro | C. C. Canada Lumber Co., Inc. | 3:17.6500 |
| 46th | 58 | Hector Rebaque / Guillermo Rojas | Porsche 914/6 | Brumos Porsche Audi Corp. | 3:18.0000 |
| 47th | 9 | Michael Summers / Bob McClure | Chevrolet Camaro | Endurance Promotions, Inc. | 3:18.1700 |
| 48th | 18 | Harry Ingle / Charles Reynolds | Ferrari 365 GTB/4 | Ring Free Oil Racing Team | 3:19.2000 |
| 49th | 19 | David McClain / Dave White | Porsche 914/6 | David H. McClain | 3:19.5700 |
| 50th | 78 | Daniel Muniz / José Luis / Ruben Novoa | Porsche 914/6 | Daniel Muniz | 3:20.1200 |
| 51st | 89 | Houghton Smith / Bert Gafford | Chevrolet Camaro | Rinzler Motoracing, Inc. | 3:20.2300 |
| 52nd | 15 | Bill Bean / Levon Pentecost | Porsche 911 S | Toad Hall Racing | 3:20.6400 |
| 53rd | 30 | Manuel Quintana / John Belperche | Shelby GT350 | Florida Tire Co., Inc. | 3:21.7900 |
| 54th | 46 | Neil Potter / Oran Ansley / Bill Hood | Ford Mustang | Sebring Racing Inc. | 3:21.9600 |
| 55th | 69 | Dieter Oest / Mike Tillson / Al Holbert | Porsche 911 T | Holbert's Porsche-Audi Inc. | 3:22.4500 |
| 56th | 41 | Peter Kirill / Russ Norburn | Porsche 911 S | Kirill Racing | 3:22.9100 |
| 57th | 76 | George Stone / Russ Poole | Porsche 911 T | Silverstone Racing Team | 3:23.5000 |
| 58th | 42 | Ralph Noseda / Jorge Garcia / Mark Livingston | Chevrolet Camaro | Garcia Racing | 3:24.3400 |
| 59th | 77 | Bruce Jennings / Bob Beasley | Porsche 911 S | Bruce Jennings | 3:26.7000 |
| 60th | 73 | Craig Ross / Jacques Groleau | Datsun 240Z | Ross Racing Ltd. | 3:31.2000 |
| 61st | 35 | Vincent Collins / Roberto Gonzalez / Jack Beall | Chevrolet Camaro | Dr. V. P. Collins | no time |