Standard SAE Flywheel Bolting
| Flywheel Pilot Dia. / Flywheel Adapter O.D. (in.) | Bolt Circle Dia. (in.) | Number of Holes | Tapped Hole in Flywheel (UNC) | SAE Flywheel Size Designation |
|---|---|---|---|---|
| 8.500 | 7.875 | 6 | 5/16-18 | 6 1/2 |
| 9.500 | 8.750 | 8 | 5/16-18 | 7 1/2 |
| 10.375 | 9.625 | 6 | 3/8-16 | 8 |
| 12.375 | 11.625 | 8 | 3/8-16 | 10 |
| 13.875 | 13.125 | 8 | 3/8-16 | 11 1/2 |
| 18.375 | 17.250 | 8 | 1/2-13 | 14 |
| 20.375 | 19.250 | 8 | 1/2-13 | 16 |
| 22.500 | 21.375 | 6 | 5/8-11 | 18 |
| 26.500 | 25.250 | 12 | 5/8-11 | 21 |
| 28.875 | 27.250 | 12 | 3/4-10 | 24 |
Heavy Duty Flywheel Bolting
| Flywheel Pilot Dia. / Flywheel Adapter O.D. (in.) | Bolt Circle Dia. (in.) | Number of Holes | Tapped Hole in Flywheel (UNC) | SAE Flywheel Size Designation |
|---|---|---|---|---|
| 8.500 | 7.500 | 8 | 3/8-16 | n/a |
| 9.500 | 8.625 | 8 | 7/16-14 | n/a |
| 10.375 | 9.500 | 8 | 7/16-14 | n/a |
| 12.375 | 11.500 | 8 | 1/2-13 | n/a |
| 13.875 | 12.500 | 8 | 5/8-11 | n/a |
| 16.000 | 14.375 | 8 | 3/4-10 | n/a |
| 18.375 | 16.750 | 8 | 3/4-10 | n/a |
| 20.375 | 18.500 | 8 | 7/8-9 | n/a |
| 22.500 | 20.500 | 8 | 1"-8 | n/a |
| 26.500 | 24.500 | 12 | 1"-8 | n/a |
| 28.875 | 26.875 | 12 | 1"-8 | n/a |