The 351 Windsor is the factory big-cube option — only installed in 1976 and 1977 Broncos. These trucks carry a premium and the engine is worth keeping. A 4-barrel carburetor, a real ignition, and a free-flowing exhaust wake it up substantially without touching the bottom end. As a swap into a non-351 truck it is only worth the trouble if you are building a heavy trail rig or already own the engine.
Ford offered the 351 Windsor (5.8L) in the Bronco for the final two model years. Net output was rated around 154 hp in the smog era — modest on paper, but the point of the 351W has never been peak horsepower. It makes meaningfully more torque than the 302, roughly 280 lb-ft versus about 220, and torque is what moves a heavy 4x4 on tall gears and big tires.
The 351W shares the 302's small-block architecture but uses a taller deck and a longer 3.50" stroke (versus 2.87"). It accepts the same accessories, the same motor mounts, and most of the same bolt-on aftermarket, which is why it drops into the Bronco's engine bay the same way a 302 does.
A loaded early Bronco on 33–35" tires asks for low-rpm grunt, not top-end power. The 351W's longer stroke delivers that — it pulls a hill at lower rpm and lugs less than a 302 in the same truck. Paired with the Dana 20's modest 2.03:1 low range (see the Dana 20 transfer case guide) and appropriate axle gearing from the gear ratio guide, the extra torque is what keeps you out of constant downshifting on the trail.
The factory smog-era 2-barrel and weak ignition leave power on the table:
The 351W carries more mass and makes more heat than the 302, and the early Bronco's small engine bay and marginal factory cooling were never generous to begin with. Low-speed crawling in summer is where these trucks overheat. Keep the factory 7-blade steel clutch fan and shroud intact, and plan a cooling upgrade alongside any 351 — a higher-capacity radiator and correct fan setup, covered in the cooling system upgrade guide, is the difference between a truck you can wheel on a hot day and one that boils over in the rocks.
If you are putting a Ford V8 into a non-351 Bronco from scratch, the carbureted 302 is cheaper, lighter on the front axle, and plenty for most builds — its details are in the factory 302 V8 guide. The 351W swap only earns its keep when you need the torque for a heavy, big-tire rig or you already have a good 351 core. If your priority is modern cold-start and altitude reliability rather than displacement, a fuel-injected 5.0L is a different path entirely — see the 302 HO / EFI swap guide.
| Part | Vendor | Est. price |
|---|---|---|
| Edelbrock Performer 600 cfm 4-bbl carburetor | Edelbrock | ~$360 |
| Edelbrock Performer 351W intake manifold | Edelbrock | ~$230 |
| Pertronix Ignitor II for 351W | Pertronix | ~$125 |
| Shorty headers, 351W (ceramic-coated pair) | Hedman / Patriot | ~$320 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.
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