Ultra 40 Plug Wire Set SBF 351W HEI Black

The Ultra 40 Plug Wire Set SBF 351W HEI Black from MOROSO is engineered for small block Ford engines running HEI ignition systems, delivering reliable spark delivery to all eight cylinders. Built for enthusiasts and mechanics who demand consistent ignition timing and thermal stability under high-performance conditions, this wire set replaces stock ignition harnesses with superior materials and design. Whether you're tuning a street engine, a weekend cruiser, or a restoration project, quality plug wires are foundational to engine reliability and throttle response.

Each of the eight wires in this set features an 8.65 mm spiral core construction that minimizes electromagnetic interference while maintaining consistent voltage transfer to the spark plugs. The 135-degree plug boots are engineered for tight, secure seating on standard spark plug terminals, preventing arcing and cross-fire that can degrade combustion efficiency. HEI-style terminal connectors ensure positive connection to the distributor cap, and the black jacket provides UV and ozone resistance for extended service life in engine bay environments prone to heat cycling and chemical exposure.

This wire set is optimized for small block Ford 351W engines paired with HEI distributors, making it an ideal upgrade when rebuilding ignition systems or diagnosing misfires caused by worn original equipment wires. Installation is straightforward—simply disconnect the old harness, route the new wires along the same path to avoid heat sources, and seat each boot firmly on the plug terminal. Mechanics and engine builders rely on MOROSO's manufacturing standards for consistent resistance values and reliable spark delivery, particularly when tuning fuel mixture or ignition advance curves for optimal horsepower and fuel economy.