| 1st | 19 | Mario Andretti / Arturo Merzario | Ferrari 512 S Spyder | Ferrari S.P.A., SEFAC | 2:33.5000 |
| 2nd | 14 | Jo Siffert / Brian Redman / Leo Kinnunen | Porsche 917 K | J. W. Automotive Engineering Ltd. | 2:34.4700 |
| 3rd | 16 | Vic Elford / Kurt Ahrens, Jr. | Porsche 917 K | Porsche Audi | 2:35.4200 |
| 4th | 20 | Peter Schetty / Jacky Ickx | Ferrari 512 S Spyder | Ferrari S.P.A., SEFAC | 2:36.2300 |
| 5th | 15 | Pedro Rodriguez / Leo Kinnunen / Jo Siffert | Porsche 917 K | J. W. Automotive Engineering Ltd. | 2:36.3100 |
| 6th | 24 | Sam Posey / Ronnie Bucknum / Bert Everett | Ferrari 512 S Spyder | N.A.R.T. | 2:36.4800 |
| 7th | 21 | Ignazio Giunti / Nino Vaccarella / Mario Andretti | Ferrari 512 S | Ferrari S.P.A., SEFAC | 2:36.6000 |
| 8th | 35 | Dan Gurney / François Cevert | Matra-Simca MS650 | Equipe Matra-Elf | 2:37.4400 |
| 9th | 31 | Piers Courage / Andrea de Adamich | Alfa Romeo T33/3 | Autodelta S.P.A. | 2:38.4700 |
| 10th | 34 | Henri Pescarolo / Johnny Servoz-Gavin | Matra-Simca MS650 | Equipe Matra-Elf | 2:39.5000 |
| 11th | 17 | Hans Herrmann / Rudi Lins | Porsche 917 K | Porsche Audi | 2:40.3200 |
| 12th | 32 | Rolf Stommelen / Nanni Galli | Alfa Romeo T33/3 | Autodelta S.P.A. | 2:40.7800 |
| 13th | 33 | Toine Hezemans / Masten Gregory | Alfa Romeo T33/3 | Autodelta S.P.A. | 2:41.3700 |
| 14th | 22 | Mike Parkes / Chuck Parsons | Ferrari 312 P Coupe | N.A.R.T. | 2:42.1900 |
| 15th | 48 | Steve McQueen / Peter Revson | Porsche 908/02 Flunder | Solar Productions, Inc. | 2:42.7500 |
| 16th | 23 | Tony Adamowicz / Luigi Chinetti, Jr. | Ferrari 312 P Coupe | N.A.R.T. | 2:43.1000 |
| 17th | 47 | Hans Laine / Gijs van Lennep | Porsche 908/02 | Racing Team AAW | 2:44.1700 |
| 18th | 45 | Richard Attwood / Gérard Larrousse / Gerhard Koch | Porsche 908/02 | International Martini Racing Team | 2:46.4300 |
| 19th | 27 | Mike De Udy / Mike Hailwood | Lola T70 Mk.3B GT Chevrolet | Grand Bahama Racing Car Co. Ltd. | 2:50.7100 |
| 20th | 30 | Piers Forester / Andrew Hedges | Ford GT40 | Trevor Graham | 2:52.2000 |
| 21st | 61 | Jim Baker / Clive Baker / Paul Richards / Bobby Rinzler | Chevron B16 Ford | Ring Free Oil Racing Team/Baker Motor Co. | 2:54.7300 |
| 22nd | 26 | Bob Brown / Gregg Young / Robin Ormes | Lola T70 Mk.3B GT Chevrolet | Randy's Auto Body | 2:57.0600 |
| 23rd | 2 | Jerry Thompson / John Mahler | Chevrolet Corvette | Troy Promotions, Inc. | 2:57.3600 |
| 24th | 62 | Brian Robinson / Hugh Kleinpeter | Chevron B16 Ford | Chevron Cars | 2:59.0200 |
| 25th | 1 | Tony DeLorenzo / Dick Lang | Chevrolet Corvette | Troy Promotions, Inc. | 2:59.6800 |
| 26th | 29 | Ray Heppenstall / Francis Grant | Ford GT40 | Auto Enterprises | 3:00.1800 |
| 27th | 4 | John Greenwood / Allan Barker | Chevrolet Corvette | John Greenwood | 3:00.2300 |
| 28th | 3 | Bob Johnson / Robert R. Johnson / Jim Greendyke | Chevrolet Corvette | Doug Bergen Racing | 3:02.8400 |
| 29th | 5 | Bill Schumacher / Bill Petree | Chevrolet Corvette | Wm. A. Schumacher | 3:03.0750 |
| 30th | 41 | Larry Bock / Larry Dent | Chevrolet Camaro | Laurel Racing (Larry Drover) | 3:06.6000 |
| 31st | 9 | Bob Grossman / Don Yenko | Chevrolet Camaro I | Marlbank Racing Team | 3:06.8900 |
| 32nd | 43 | John Tremblay / Bill McDill | Chevrolet Camaro I | Bruce Behens Racing | 3:07.1500 |
| 33rd | 40 | Vince Gimondo / Chuck Dietrich | Chevrolet Camaro I | Takondo Racing | 3:07.3800 |
| 34th | 50 | Mike Rahal / Hugh Wise / Werner Frank | Porsche 906 | Nationwide Food Brokers Racing Team | 3:07.4000 |
| 35th | 8 | Dave Heinz / Or Costanzo | Chevrolet Corvette | Or Costanzo | 3:07.4700 |
| 36th | 51 | Stephen Behr / Merv Rosen | Porsche 906 | Porsche Audi VWNC | 3:11.6000 |
| 37th | 25 | Harley Cluxton / Wilbur Pickett | Ferrari 275 GTB/C | Harley E. Cluxton, III | 3:15.9400 |
| 38th | 38 | Don Kearney / Joie Chitwood | Chevrolet Camaro | David H. McClain | 3:14.7100 |
| 39th | 49 | Sepp Greger / Andreas Schmalbach | Porsche 910 | Josef Greger | 3:16.5500 |
| 40th | 67 | Jim Bandy / Fred Stevenson | Lotus 47 | Sport Motors | 3:17.0300 |
| 41st | 54 | Anatoly Arutunoff / Bill Pryor | Abarth 2000 SP (SE010) | Automobiles of Italy, Inc. | 3:17.1300 |
| 43rd | 63 | Carlos Fabre / Pepe Aguilar | Chevron B8 BMW | Carlos Fabre | 3:18.0100 |
| 44th | 53 | Peter Gregg / Pete Harrison | Porsche 911 T | Brumos Porsche Audi Corp. | 3:18.3300 |
| 45th | 39 | Charlie Kemp / Bob Mitchell | Chevrolet Camaro | Robert B. Mitchell | 3:19.0300 |
| 46th | 77 | Bruce Jennings / Bob Tullius | Porsche 911 T | Bruce Jennings | 3:19.9700 |
| 47th | 91 | Jim Corwin / Donna Mae Mims | Chevrolet Camaro I | Flem-Cor Enterprises | 3:21.9800 |
| 48th | 37 | Vincent Collins / Larry Wilson | Ford Mustang | Collins-Wilson Racing | 3:22.7800 |
| 49th | 52 | Jacques Duval / Bob Bailey / George Nicholas | Porsche 911 T | Jacques Duval | 3:23.1000 |
| 50th | 73 | Janet Guthrie / Rosemary Smith / Judy Kondratiff | Austin-Healey Sprite | Ring Free Oil Racing Team/Baker Motor Co. | 3:24.2000 |
| 51st | 36 | Ray Cuomo / Bernard Gimbel / George Lisberg | Ford Mustang | Ray Cuomo Racing | 3:26.3600 |
| 52nd | 92 | Don Gwynne / John Elliott | Chevrolet Camaro I | Preston Hood Chevrolet, Inc./John Elliott | 3:17.3800 |
| 52nd | 74 | Ralph Meaney / Bill Bean | Porsche 911 T | Ralph Meaney, Inc. | 3:28.2900 |
| 53rd | 59 | Reggie Smith / Dean Donley / Omar Buttari | MG Midget | Waldron Motors | 3:28.9400 |
| 54th | 7 | Bruce Morehead / Milo Vega | AMC AMX | Bruce Morehead Racing | 3:30.3400 |
| 55th | 56 | Jon Woodner / Dan O'Connor | MG Midget | British Leyland Motors Inc. | 3:32.6800 |
| 56th | 57 | John Belperche / Jim Gammon / Ray Mummery | MGB | Waldron Enterprises Inc. | 3:34.2600 |
| 57th | 55 | Merle Brennan / Logan Blackburn | MGB | British Leyland Motors Inc. | 3:34.6000 |
| 58th | 58 | Ben Scott / Dave Houser / Lowell Lanier | MGB | Waldron Enterprises Inc. | 3:39.5700 |
| 59th | 82 | Robert Clark / Wayne Marsula | Lancia Fulvia HF | General Plastics | 3:39.6200 |
| 60th | 80 | Rod Kennedy / Mike Tillson / Robert Samm | Lancia Fulvia HF | Texas Speed Museum | 3:43.1800 |
| 61st | 97 | Walter Brown / Buzz Marcus / Jim Sandman | BMW 2002 | HCAS, Inc. | 3:45.3800 |
| 62nd | 79 | Del Russo Taylor / Buzz Dyer | Alfa Romeo 1750 GTV | Del Taylor | 3:46.7900 |
| 63rd | 18 | Paul Pettey / Roy Hallquist | Ford Mustang | Paul Pettey | 3:47.0900 |
| 64th | 87 | Robert Whitaker / Harvey Eckoff / Jack Slottag | Volvo 122 S | Robert W. Whitaker | 3:47.1700 |
| 65th | 60 | Robert Kilpatrick / Don Goodrich | MGB | Herrington Motors | 3:51.1000 |
| 66th | 86 | Ron Polimeni / Robert Theall | Volvo 122 S | Sandy's Spares | 3:52.3800 |
| 67th | 88 | Paul Fleming / Amos Johnson / Bill Bowers | Fiat 124 Coupe | Simone N. Fleming | 3:53.2400 |
| 68th | 69 | Paul Spruell / Wilbur Pickett | Alfa Romeo Giulia Spider | Scuderia Spruell | 3:57.9000 |
| 69th | 46 | Gerhard Koch / Gérard Larrousse / Richard Attwood | Porsche 908/02 | International Martini Racing Team | no time |