| 1965 Fullsize Speedometer Gear usage Chart | ||||||||||||
| Driven Gear Or Sleeve | Tire Size | Speedometer Adapter | ||||||||||
| Rear End Ratio | Part # | Teeth | Color | 8.25 x 14 | 8.55 x 14 | 8.15 x 15 | 8.45 x 15 | Model | Ratio | Part # | Color | Fitting & Seal Assy |
| 4.11 | 9780523 | 17 | black | X | 6660-AJ | .9705 | 9777006 | RED | 3869914 | |||
| 4.11 | 9780522 | 18 | green | X | 3869914 | |||||||
| 4.11 | 9780522 | 18 | green | X | 6660-AJ | .9705 | 9777006 | RED | 3869914 | |||
| 3.55 | 3987920 | 20 | blue | X | 3899912 | |||||||
| 3.55 | 3860344 | 21 | red | X | X | 3899912 | ||||||
| 3.73 | 3860342 | 19 | natural | X | X | 666-AJ | .8653 | 9775436 | BLUE | 3899912 | ||
| 3.73 | 3860344 | 21 | red | X | 3899912 | |||||||
| 3.42 | 3460342 | 19 | natural | X** | 6660-AJ | .9705 | 9777006 | RED | 3899912 | |||
| 3.42 | 3987920 | 20 | blue | X | X | 3899912 | ||||||
| 3.42 | 3987920 | 20 | blue | X** | 6660-AJ | .9705 | 9777006 | RED | 3899912 | |||
| 3.23 | 3860341 | 18 | brown | X | 6660-AJ | .9705 | 9777006 | RED | 3899912 | |||
| 3.23 | 3860342 | 19 | natural | X | X | X** | 3899912 | |||||
| Note: X**= Used with police option | ||||||||||||
| Information supplied by George Pearson, taken from a Pontiac Parts Book | ||||||||||||