1971 Ford Mustang Facts: Specs, Models, and Engine Options

Picture this: It’s September 1970, and Ford just pulled the covers off what they’re calling the 1971 Mustang. Anyone expecting another iteration of the car they’d grown familiar with got something else entirely. The whole thing looked different, moved different, and honestly felt like Ford decided to start fresh while keeping the name badge. Over 151,000 of these rolled off the line that year, each one representing some version of what Ford thought the Mustang should be as the 1960s faded further into memory.

That Radical New Look

The 1971 model bore no resemblance to what came before. Not a little different or evolutionary, just completely new. Ford’s designers threw out the old playbook and came back with longer lines, different proportions, and a stance that made the car look simultaneously bulkier and lower. Whether you loved it or hated it probably depended on how attached you were to the first-generation cars, but nobody could ignore it.

Five Ways to Buy One

Ford offered the ’71 in five distinct body styles: hardtop, fastback, Mach 1, convertible, and Grande. Each one carried its own vibe, its own weight, its own price tag. The SportsRoof fastback started things off at a relatively accessible $3,070, while the convertible commanded a premium at $3,325. Every single one seated four people, came with two doors, and rode on a 109-inch wheelbase that stretched out longer than earlier Mustangs.

The Boss 351 Arrives

Ford killed off both the Boss 302 and Boss 429 from previous years and replaced them with something new: the Boss 351. This thing came with a 330 horsepower 351-4V Cleveland engine, an electronic RPM limiter, and a Hurst shifter controlling a wide-ratio 4-speed manual. The front spoiler was functional, not just decorative, and it shipped knocked down so dealers could install it. F60-15 AWL tires wrapped around the wheels, and the whole package included a Traction-lock differential that actually helped put that power down instead of just spinning one wheel uselessly.

Dimensions That Defined the Space

Every ’71 Mustang measured 187.5 inches long and 75 inches wide. The front tread ran 61.5 inches while the rear came in at 60 inches. Height varied depending on what you bought: hardtops and convertibles stood 51.5 inches tall, fastbacks measured 50.6 inches, and Mach 1s squatted lowest at 50.4 inches. That 109-inch wheelbase gave the car a different feel than the earlier, tighter designs, changing how it rode and how it felt planted at speed.

Weight Distribution Across the Lineup

The SportsRoof weighed in at 2,995 pounds, making it the lightest option. The Grande added another 55 pounds to hit 3,050, or 3,177 if you opted for the vinyl roof. Fastbacks came in at 3,121 pounds, while the Boss 351 weighed 3,141. Hardtops tipped the scales at 3,151, Mach 1s at 3,172, and convertibles topped everything at 3,273 pounds. That spread of nearly 300 pounds from lightest to heaviest meant performance varied significantly depending on which body you chose, even with the same engine.

The Base Six-Cylinder

Ford’s entry-level engine was an inline six-cylinder displacing 250 cubic inches, or 4.1 liters if you prefer metric. It made 150 horsepower at 4,000 RPM and delivered 296 foot-pounds of torque at 2,600 RPM. Not exactly thrilling, but it moved the car adequately and kept insurance costs reasonable. Plenty of people bought Mustangs with this engine and never felt particularly cheated, especially if they cared more about the shape than the speed.

The 302 V-8 Option

Step up to the 302 cubic inch V-8, and you got 210 horsepower at 4,600 RPM along with that same 296 foot-pounds of torque at 2,600 RPM. The 4.9-liter displacement sat in that sweet spot where it delivered noticeably more performance than the six without drinking fuel like the bigger engines or requiring high-test gas. For a lot of buyers, this was the goldilocks engine: enough to have fun, not so much that you paid through the nose to feed it.

Two Flavors of 351

The 351 cubic inch V-8 came in two versions. The two-barrel carburetor setup produced 240 horsepower at 4,600 RPM. Opt for the four-barrel version, and horsepower jumped to 330 at 5,400 RPM. That’s a significant difference from the same displacement, and it showed in how the car pulled through the rev range. The 5.8-liter 351 became a favorite among people who wanted serious performance without going all the way to the monster big-blocks.

The 429 Cobra Jet

Then there was the 429 Cobra Jet, displacing 7.0 liters and producing 370 horsepower at 5,400 RPM. The bore and stroke measured 4.362 by 3.950 inches, and the compression ratio sat at 11.30:1, meaning it really wanted premium fuel. This engine transformed the car’s character completely, adding weight up front but delivering thrust that made the extra heft feel irrelevant once you got moving. The 429 represented one of the largest displacements Ford ever stuffed into a Mustang.

The Super Cobra Jet

Above the Cobra Jet sat the Super Cobra Jet, same 429 cubic inches but tuned to deliver 375 horsepower at 5,600 RPM. Still running that 11.30:1 compression ratio, still demanding premium fuel, but with internals that could handle sustained high-RPM abuse better than the standard Cobra Jet. The difference might seem small on paper, but the Super Cobra Jet felt more willing to rev, more eager to stay in the power band longer.

Boss 351 Cooling and Electrical

The Boss 351 didn’t just get a special engine. Ford included a dedicated cooling package designed to handle the heat that 330-horsepower Cleveland generated under hard use. An 80-ampere battery replaced the standard unit, providing more reserve capacity for repeated starts and supporting the upgraded electrical demands. These weren’t flashy upgrades, but they mattered when you actually drove the car hard rather than just posing in parking lots.

Standard Transmission

Every 1971 Mustang came standard with a 4-speed manual transmission. The Boss 351 got the Hurst shifter, which felt tighter and more precise than the standard setup. That wide-ratio gearbox in the Boss meant longer legs between gears, better suited to sustained high-speed running than stop-and-go traffic. You could opt for an automatic in most models, but the 4-speed manual was what Ford expected enthusiasts to choose.

Boss 351 Instrumentation

The Boss 351 came standard with an Instrumentation Group that included gauges beyond what base models offered. Oil pressure, ammeter, temperature—the stuff you actually need to monitor when you’re running an engine hard. This wasn’t just about looking sporty; it was about giving the driver real information about what the car was doing mechanically.

The Grande’s Upscale Touch

The Grande trim positioned itself as the gentleman’s Mustang, adding upscale interior and exterior touches that separated it from the more performance-focused variants. At $3,115 to $3,210 depending on options, it cost more than the base hardtop but delivered a quieter, more refined experience. This was Ford acknowledging that not everyone buying a Mustang wanted to feel every road imperfection or hear every engine revolution echoing through the cabin.

Convertible Compromises

The convertible weighed 3,273 pounds, making it the heaviest Mustang you could buy in 1971. That extra weight came from structural reinforcements needed to maintain rigidity without a fixed roof. At $3,325, it also commanded the highest price. But people bought it anyway because driving a Mustang with the top down carried its own appeal, physics and pricing be damned. The convertible maintained that connection to the original Mustang’s promise of open-air motoring.

Mach 1 Middle Ground

The Mach 1 sat between family-friendly and hardcore performance, weighing 3,172 pounds and standing 50.4 inches tall. It came with sportier styling cues than the hardtop but didn’t go as far as the Boss 351 in terms of pure performance hardware. This made it popular with people who wanted the Mustang’s sporty image without committing to the full Boss experience or settling for the base model’s more conservative appearance.

That Long Wheelbase

The 109-inch wheelbase represented a significant departure from earlier Mustangs. It improved ride quality and high-speed stability, though some argued it hurt the car’s nimble character. Ford made this choice deliberately, trying to position the Mustang as a more mature, refined vehicle rather than the tight, darty sports car it started as. Whether this was progress or compromise depended entirely on what you valued in a Mustang.

Competing Across Market Segments

With engines ranging from a 150-horsepower inline-six to a 375-horsepower Super Cobra Jet, and body styles spanning from the stripped-down SportsRoof to the upscale Grande, Ford tried to make the 1971 Mustang competitive everywhere. You could outfit one as a budget cruiser, a luxury tourer, a drag strip weapon, or anything in between. This strategy meant Ford could theoretically sell Mustangs to almost anyone, though it also risked diluting what the Mustang nameplate actually represented.

The 1971 Mustang exists now as this interesting artifact of Ford trying to figure out what a pony car should be in a changing market. The emissions regulations were tightening, insurance companies were getting hostile toward performance cars, and buyers were starting to care more about comfort and fuel economy. Ford’s response was to offer everything simultaneously, letting customers choose their own compromise. Some of these cars became collectibles, particularly the Boss 351s. Others just served as transportation until they wore out and got scrapped. But all 151,428 of them represented Ford’s attempt to keep the Mustang relevant as the muscle car era started its slow decline into something else entirely.