How much horsepower does a 1971 351 Mustang have?
In 1971, a Mustang with a 351 cubic-inch V8 could produce roughly 250 to 330 horsepower, depending on the exact engine configuration. The range reflects the different 351 Windsor and 351 Cleveland setups offered that year.
To understand this question in more detail, Ford offered two families of 351 engines for the Mustang in 1971—the Windsor and the Cleveland—with both 2-barrel (2V) and 4-barrel (4V) carburetor versions. The horsepower figures published at the time were gross ratings, measured before drivetrain losses, and actual in-car performance could vary based on exhaust, cam timing, compression, and condition. The following breakdown outlines the common factory figures you’d see for each configuration.
351 Windsor engines in the 1971 Mustang
The Windsor family was a popular and robust option, available in 2V and 4V forms.
- 351W 2V (two-barrel): approximately 250 hp gross; torque around 380–395 lb-ft.
- 351W 4V (four-barrel): approximately 290–300 hp gross; torque around 395–400+ lb-ft.
Note: These figures are gross horsepower from era brochures; real-world output with a complete drivetrain is typically lower.
351 Cleveland engines in the 1971 Mustang
The Cleveland family offered higher-end performance in the 4V configuration, with 2V variants delivering strong mid-range power.
- 351C 2V (two-barrel): roughly 275–285 hp gross; torque around 360–380 lb-ft.
- 351C 4V (four-barrel): roughly 330 hp gross; torque around 370–380 lb-ft.
As with the Windsor variants, these are gross ratings; actual drivetrain horsepower would be lower when measured at the wheels.
Additional notes on horsepower and context
The 1971 Mustang lineup included performance-oriented models and options such as the Mach 1, which could be equipped with any of the 351 variants. Because horsepower numbers from that era were published as gross ratings, they don’t directly translate to modern net horsepower figures. If you’re evaluating a specific car, checking the original build sheet, window sticker, or an engine code can help confirm the exact configuration and expected performance.
Summary
In brief, a 1971 Mustang fitted with a 351 engine could exhibit roughly 250–300 hp for Windsor-based configurations or about 330 hp for the 351 Cleveland 4V option, all reported as gross horsepower by Ford at the time. The precise figure depends on whether the car used a Windsor or Cleveland block and whether it carried 2V or 4V carburetion. For a precise, car-by-car assessment, consult the dealership records or a certified engine build sheet.
