Boss returned for one more year, this time wearing the new-for-1971 sheet metal marking a longer, lower and wider Mustang than ever before. Under the hood, changes were equally dramatic, with the company’s 351 Cleveland V8 supplying the basis for motivation, matched as always with a four-speed manual gearbox. But with Ford pulling out of all factory-sponsored motorsports after 1970, the Boss 351 was denied a key element cementing the status of its predecessors: the proof testing provided by an official racing program.
Still, the Ford Mustang Boss 351 offered exciting performance and eye-catching looks aided by the 60-degree sloping fastback body and twin-scoop contrasting hood. Interiors also gained luxury options; coupled with the improved tractability of the 351 Cleveland engine, it was easier for prospective buyers to turn this final early Boss into a comfortable high-speed cruiser than was possible with the race-bred 302 and 429 iterations.
1971 Boss 351 specifications:
- 351-cubic-inch (5.8-liter) OHV V8
- 330 hp @ 5800 rpm
- 380 lb.-ft. @ 3400 rpm
- Four-speed manual