1971 Ford Mustang Axle Information & Ratios
| Ratio | Locking | 1969 | 1970 | 1971 | 1972 | 1973 |
| 2.35 | F | |||||
| 2.75 | 2 | 2 | 2 | 2 | 2 | |
| 2.75 | Locking | K | K | K | K | K |
| 2.79 | 3 | 3 | 3 | 3 | 3 | |
| 2.80 | 4 | 4 | 4 | |||
| 2.80 | Locking | M | M | M | ||
| 2.83 | 5 | 5 | ||||
| 3.00 | 6 | 6 | 6 | 6 | 6 | |
| 3.00 | Locking | O | O | |||
| 3.07 | B | B | ||||
| 3.08 | C | C | ||||
| 3.08 | Locking | U | ||||
| 3.10 | 7 | |||||
| 3.20 | 8 | |||||
| 3.25 | 9 | 9 | 9 | |||
| 3.25 | Locking | R | R | R | ||
| 3.50 | A | A | 9 | A | 9 | |
| 3.50 | Locking | S | S | R | S | R |
| 3.89 | A | |||||
| 3.89 | Locking | S | ||||
| 3.91 | Locking | V | V | V | ||
| 4.11 | Locking | V | ||||
| 4.30 | Locking | W | W | Y |
| Axle code | Ratio and type |
| 2 | 2.75 Open differential |
| K | 2.75 locking differential |
| 3 | 2.79 Open differential |
| 4 | 2.80 Open differential |
| M | 2.80 locking differential |
| 6 | 3.00 Open differential |
| B | 3.07 Open differential |
| 9 | 3.50 Open differential |
| R | 3.50 locking differential |
| A | 3.89 Open differential |
| S | 3.89 locking differential |
| V | 4.11 Locking differential |
| Y | 4.30 Locking differential |
