| 1970 Grand Prix Speedometer Gear usage Chart | |||||||||||||
| Driven Gear Or Sleeve | Tire Size | Speedometer Adapter | |||||||||||
| Rear End Ratio | Part # | Teeth | Color | F78 X 14 | G70 X 14 | G78 X 14 | H78 X 14 | Model | Ratio | Part # | Color | Trans Code | Drive Gear Teeth |
| 3.07 | 3870351 | 17 | PURPLE | X | DJ | 7 | |||||||
| 3.23 | 3870351 | 17 | PURPLE | X | DG | 7 | |||||||
| 3.31 | 3860341 | 18 | BROWN | X | DG-DJ-DP | 7 | |||||||
| 3.55 | 3860342 | 19 | NATURAL | X | DJ | 7 | |||||||
| Information supplied by George Pearson, taken from a Pontiac Parts Book | |||||||||||||