Classic Cougar Drive Trains: 1971
Cleveland 351 4V
1971 Engines:
The Cleveland 351 2V remained the Cougar's standard engine for 1971, but it lost 10 horsepower and a little torque in the model year changeover.
When the 1971 models were introduced there were three optional engine choices: a slightly de-tuned 351 4V, the new CJ 429 4V and the CJ 429 with Ram Air. On 5/17/71 a "CJ" version of the 351 (280 h.p.) was added.
| CID | Carb | CR | HP | Torque | Exhaust | Std/Opt | VIN Code | Specs |
| 4291 | 4 bbl | 11.3:1 | 370@5400 | 450@3400 | dual | optional | C |  |
| 351 | 2 bbl | 9:1 | 240@4600 | 350@2600 | single | standard | H | |
| 4292 | 4 bbl | 11.3:1 | n/a | n/a | dual | optional | J | n/a |
| 351 | 4 bbl | 10.7:1 | 285@5400 | 370@3400 | dual | optional | M | |
| 3513 | 4 bbl | 9:1 | 280@5800 | 350@3800 | dual | optional | Q | |
NOTES:
(1) CJ 429
((2) CJ 429 w/Ram Air
(3) CJ 351 -- introduced 5/17/71
1971 Transmissions:
| Type | Ranges | Eqpmnt Code |
| Manual1 | 3-speed | 1 |
| Manual2 | 4-speed | 5 |
| Automatic (C-6)--Select Shift3 | 4-speed | U |
| Automatic FMX5 | 3-speed | X |
NOTES:
(1) Standard with 351 engines
(2) Optional with all engines
(3) Optional with 351 4V & 429
(4) Optional with 351 2V
1971 Rear Axle Ratios:
| Eqpmnt Code | Non-Locking | Locking |
| 2 | 2.75 | - |
| 3 | 2.79 | - |
| 4 | 2.80 | - |
| 6 | 3.00 | - |
| 9 | 3.25 | - |
| A | 3.50 | - |
| K | - | 2.75 |
| M | - | 2.80 |
| Q | - | 3.00 |
| R | - | 3.25 |
| S | - | 3.50 |