PORSCHE RACING HISTORYJohn O'Steen (USA)
1973
4 February 1973 - Daytona 24 Hours - World Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 43 | Porsche 911 S | 911 230 0921 | GT+2.0 | Dave Helmick (USA)/John O'Steen (USA)/Stephen Behr (USA) | Dave Helmick (USA) | 11th | 8th | 31st | 558 laps |
21 July 1973 - Watkins Glen 6 Hours - World Championship for Makes
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 43 | Porsche 911 Carrera RSR | 911 360 0915 | GT | Dave Helmick (USA)/John O'Steen (USA) | Ecurie Escargot (USA) | 12th | 4th | 24th | 164 laps |