The 1971 Boss 351 replaced the previous Bosses and became known as the performance Mustang. There were 1,806 of these special cars made. They came with very few options, including:
- Boss engine,
- ram air,
- 3.91 rear axle,
- 4 speed manual transmission,
- competition suspension,
- Front power disc brakes
- Front spoiler,
- Mach 1 front grill
- Mach 1 lower body side paint
- 351 decals and tape treatment,
- Chrome front bumper
- Hood that was mostly blacked out.
- 15×7 wheels and chrome trim rings
- Goodyear F60x15 RWL tires
The original Boss of 1969-70, the Boss 302, was a homologation model, produced to meet the eligibility requirements of the SCCA Trans-Am series. It used a high-revving 302-cid V-8 rated at 290 horsepower, built to meet the race series’ five-liter class limit.
Ford, however, had ended its Trans-Am program by the time the bigger, heavier Boss 351 arrived late in the 1971 model year. Though it lacked a racing pedigree, the new Boss turned out to be one of the fastest Mustangs of the day. It was also one of the rarest, with just 1,806 built.
“The Boss 351 was more drag-racing oriented than the Boss 302, but better handling than the 429 Cobra Jet,” said Mike Berardi, global director of service engineering operations at Ford Motor. A red Boss 351 is one of 55 Mustangs in his collection, and a favorite to drive. “It’s high revving, so you row the gears more than with a 429 CJ,” he said.
The 351 in the ’71 Boss was Ford’s 351-cid Cleveland engine, nicknamed for the Ohio plant that built it. The 351C shared little more than bore and stroke spacing dimensions with the 351 Windsor used in the 1969 Mustang. Its advantage was deeper breathing, a result of huge ports and valves in the cylinder heads. The 1969-70 Boss 302 had married the Windsor block with Cleveland heads, but the Boss 351 was the whole deal, with lots more torque.
Starting with the 11:1-compression 351C with four-barrel carburetor, Ford assembled a hot rodder’s wish list: four-bolt mains; forged pistons; shot-peened connecting rods; high-lift camshaft; aluminum intake with 750-cfm carburetor; dual-point ignition and ram air induction. It added up to 330 horsepower at 5,400 rpm and 370 pound-feet of torque at 4,000 rpm, matching Chevy’s LT-1 350 in the 1971 Camaro Z28. Magazines that tested the Boss 351 posted quarter-mile times in the low-14-second range at about 100 mph, on par with big-block models like the Mustang 429 CJ.
Download the 1971 BOSS 351 Brochure