351 Windsor Engine

Specifications

The Ford 351 Windsor engine is a 351-cubic-inch (5.8L) small-block V8 featuring a pushrod OHV design, a 4.00-inch bore, and a 3.50-inch stroke. It uses a cast-iron block with a 9.5-inch deck height and typically came with cast-iron cylinder heads, though aftermarket aluminium options are common. Depending on the year and configuration, factory compression ratios generally ranged from about 8.0:1 to 10.7:1, with horsepower output spanning roughly 150–300+ hp and torque often exceeding 350 lb-ft. The engine uses a reliable five-main-bearing bottom end, hydraulic lifters, and a durable oiling system.

The 351 Windsor engine is Ford’s original 351-cubic-inch small-block V8. Featuring a traditional pushrod valvetrain, a 4.00-inch bore, and a 3.50-inch stroke. This engine is built with a strong cast-iron block and a taller deck height, delivering a solid low-end torque and long-term durability. Its dependable oiling system, thick cylinder walls, and huge aftermarket support have made it a favorite choice among hot-rodders, off-road enthusiasts, and restomod builders. Thanks to the wide availability of performance parts such as high-flow cylinder heads, improved intake manifolds, stoker kits, and modern EFI conversions making the 351W remain one of the Ford’s most versatile and modification-friendly V8 engines. 

Engine Variants

Boss 351 (1971)

This high performance version of Ford’s 351 Cleveland V8, features a 351 cu in (5.8L) displacement with a 4.00-inch bore and 3.50-inch stroke, solid-lifter camshaft, and high-flow 4V canted-valve heads. It ran an 11.7:1 compression ratio and was factory rated at 330 hp and around 370 lb-ft of torque. The engine used a dual-plane aluminum intake topped with a 750 CFM Autolite four-barrel carburetor, a functional Ram Air induction system, and a forged steel crankshaft with heavy-duty rods and pistons.

Additional performance components included a high-capacity cooling system, performance ignition, and a rev limiter. Known for its strong mid- and high-rpm power, the Boss 351 is widely regarded as one of Ford’s most potent small-block engines of the muscle car era.

351 High Output (H.O.) (1971–1973)

The 351 High Output (H.O.) from 1971–1973 was a performance version of Ford’s 351 Cleveland V8. It kept the same 351 cu in (5.8L) size with a 4.00-inch bore and 3.50-inch stroke but used stronger internal parts and a hotter cam to make more power than the standard engine. Early versions (1971) used the high-flow 4V heads, while the 1972–73 versions used 2V heads with open chambers but still kept performance-focused tuning. Depending on the year, compression ratios ranged from about 8.6:1 to 10.7:1, and horsepower ratings ran roughly from 246–275 hp (net).

The engine came with a four-barrel carburetor, dual exhaust, and better ignition components. Overall, the 351 H.O. was built as a tougher, quicker-revving version of the regular 351C, giving drivers stronger acceleration and better high-rpm performance in an era when most engines were losing power due to emissions rules.

351 Cobra Jet (CJ) (1971–1972)

The 1971–1972 351 Cobra Jet (CJ) was a performance version of Ford’s 351 Cleveland V8, with a 351 cu in (5.8L) displacement, 4.00-inch bore, and 3.50-inch stroke. It featured high-flow 4V cylinder heads, a four-barrel carburetor, a performance camshaft, and a dual-plane intake for strong mid- and high-rpm power. With a compression ratio around 8.6:1, it produced approximately 266–275 hp and robust torque. The engine included reinforced internal components, dual exhaust, and an optional Ram Air induction system, making it a durable and high-performing small-block V8 of the early 1970s.

Frequently Asked Questions