PORSCHE RACING HISTORYGary Altman (USA)
1987
21 March 1987 - Sebring 12 Hours - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 13 | Porsche 914/6 | GTU | Gary Altman (USA)/Mark Altman (USA)/Tim Selby (USA) | Altman Bros. Motor Racing (USA) | 59th | 15th | 60th | 68 laps - Gearbox |
16 August 1987 - Road America 500 Miles - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 20 | Porsche 914/6 | GTU | Mark Altman (USA)/Gary Altman (USA) | Altman Bros. Motor Racing (USA) | 28th | 6th | 51st | 66 laps |