Exhaust Headers for Ford F150 F250 F350 (1977-1979) 4WD

High-Flow Exhaust Headers for 1977-1979 Ford F-150, F-250, F-350 (335-Series / Dentside)

Designed specifically for 4WD applications, these 4-1 exhaust headers replace restrictive factory cast manifolds to improve exhaust scavenging and lower cylinder head temperatures.

The Stock Dentside Exhaust Restriction

The OEM cast iron exhaust manifolds on the 351M and 400M engines are notoriously inefficient, prioritizing tight factory packaging over optimal flow characteristics. As these dense iron castings age, they are prone to severe heat cycling degradation, leading to stress cracks and exhaust leaks at the cylinder head mating surfaces. Furthermore, the abrupt angles and narrow internal passages of the stock manifolds cause excessive exhaust backpressure. This restriction prevents the 335-Series engines from properly evacuating spent gasses during the exhaust stroke, creating a thermal choke point that elevates under-hood temperatures, increases heat soak potential, and severely limits low-end torque output—a critical flaw when towing, hauling, or navigating trails with your heavy 4WD truck.

The Engineering Solution

These upgraded exhaust headers utilize a 2x 4-1 racing design to drastically optimize flow dynamics. Constructed from heavy-duty 16-gauge iron piping with a durable black-coated finish, the system features 1-5/8\" outside diameter primaries that transition smoothly into large 3\" OD collectors. This precise configuration enhances scavenging by maintaining exhaust gas velocity, effectively pulling successive exhaust pulses out of the cylinders to improve volumetric efficiency. The headers feature thick CNC-machined flanges and robust TIG welding to prevent the warping and gasket blowout issues common to stamped factory equivalents. By mitigating backpressure, this setup yields immediate, tangible gains of 10 to 15 horsepower and proportional torque. The included 3\" to 2-1/2\" weldable reducers ensure seamless integration into custom dual exhaust systems.

Technical Specifications

Compatibility

• 1977-1979 Ford F-150 Pickup Truck 5.8L (351M) & 6.6L (400M) V8, 4WD Model Only
• 1977-1979 Ford F-250 Pickup Truck 5.8L (351M) & 6.6L (400M) V8, 4WD Model Only
• 1977-1979 Ford F-350 Pickup Truck 5.8L (351M) & 6.6L (400M) V8, 4WD Model Only
• 1978-1979 Ford Bronco 5.8L (351M) & 6.6L (400M) V8, 4WD Model Only
• Note: Only Fit 351M-400M, 4WD Models. Excludes Windsor Motors And All 2WD Models.

The Ford Truck Durability Standard

Built to handle the rigorous demands of off-road trails and heavy-duty towing, these headers provide the critical thermal management and robust low-end torque required to maximize the rugged utility of your classic 4WD Dentside Ford.