| 1970 Tempest/GTO Speedometer Gear Usage Chart (Turbo 400) | |||||||||||||
| Speedo Driven Gear | Tire Size | Speedometer adapter | |||||||||||
| Rear axle ratio | Part No. | Teeth | Color | G70 X 14 | G78 X 14 | H78 X 14 | Part No. | Color | Sleeve & seal assy. | Trans code | Drive gear teeth | ||
| 2.56 | 9780628 | 35 | PINK | X | X | 1362294 | PT | 18 | |||||
| 2.56 | 1362048 | 40 | BLACK | X | 1362293 | PT | 18 | ||||||
| 2.78 | 1359272 | 38 | BLUE | X | X | 1362294 | PT | 18 | |||||
| 2.78 | 1359270 | 36 | WHITE | X | 1362294 | PT | 18 | ||||||
| 3.07 | 1359272 | 38 | BLUE | X | 1362294 | PR | 16 | ||||||
| 3.07 | 1359271 | 37 | RED | X | 1362294 | PR | 16 | ||||||
| 3.08 | 1362049 | 42 | GREEN | X | X | 1362293 | PT | 18 | |||||
| 3.08 | 1362048 | 40 | BLACK | X | 1362293 | PT | 18 | ||||||
| 3.23 | 1362048 | 40 | BLACK | X | 1362293 | PD/PY | 16 | ||||||
| 3.31 | 1362195 | 41 | YELLOW | X | 1362293 | PR | 16 | ||||||
| 3.55 | 9780470 | 44 | DK GREY | X | 1362293 | PD/PY | 16 | ||||||
| 3.55 | 1362196 | 43 | PURPLE | X | 1362293 | PD/PY | 16 | ||||||
| 3.90 | 1359271 | 37 | RED | X | 535615 | 1362294 | PD/PY | 16 | |||||
| 4.33 | 1359273 | 39 | BROWN | X | 535614 | 1362294 | PD/PY | 16 | |||||
| Information supplied by George Pearson, taken from a Pontiac Parts Book | |||||||||||||