PORSCHE RACING HISTORYPreston Henn (USA)
1983 : Daytona 24 Hours - 1st overall
6 February 1983 - Daytona 24 Hours - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 6 | Porsche 935 L | 935 L | GTP | Bob Wollek (F)/Claude Ballot-Léna (F)/Preston Henn (USA)/A. J. Foyt (USA) | Henn's Swap Shop Racing (USA) | 1st | 1st | 1st | 618 laps |
24 April 1983 - Riverside 6 Hours - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 6 | Porsche 935 K3 | 000 0009 | GTP | Michael Andretti (USA)/A. J. Foyt (USA)/Mario Andretti (USA)/Preston Henn (USA) | PPG Industries (USA) | 20th | 7th | 9th | 154 laps - DNF |
8 May 1983 - Silverstone 1000 km - World Endurance Championship
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 47 | Porsche 956 | 956-103 | C | Preston Henn (USA)/Guy Edwards (GB)/Rupert Keegan (GB) | Henns' T-Bird Swap Shop | DNF | 11th | 54 laps - Engine |
19 June 1983 - Le Mans 24 Hours - World Endurance Championship
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 47 | Porsche 956 | 956-103 | C | Preston Henn (USA)/Claude Ballot-Léna (F)/Jean-Louis Schlesser (F) | Henns' T-Bird Swap Shop | 10th | 10th | 23rd | 327 laps |
21 August 1983 - Road America 500 Miles - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 1 | Porsche 935 L | 935 L | GTP | John Paul, Jr. (USA)/Preston Henn (USA) | Henn's Swap Shop Racing (USA) | 33rd | 8th | 3rd | 63 laps - DNF |
2 October 1983 - Fuji 1000 km - World Endurance Championship
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 48 | Porsche 956 | 956-103 | C | Preston Henn (USA)/Kunimitsu Takahashi (J)/John Paul, Jr. (USA) | Alpha Racing | DNF | 9th | 64 laps - Contact |