Ultra 40 Plug Wire Set SBC Over V/C HEI Black

The Ultra 40 Plug Wire Set SBC Over V/C HEI in black is a premium ignition system upgrade designed for small-block Chevrolet engines running over-the-valve-cover HEI distributors. This complete plug wire set addresses a critical need in classic and modified engine builds where traditional under-hood routing isn't feasible or desirable. Built by Moroso—a trusted name in performance ignition products for over five decades—these wires deliver reliable spark delivery while accommodating the unique geometry demands of over-the-valve-cover HEI installations.

Ultra 40 wires feature low-resistance conductor technology engineered to minimize electrical loss and reduce electromagnetic interference, critical factors in high-RPM performance and fuel-injected applications. The black polyvinyl jacket resists heat, ozone, and UV degradation—essential protection in engine compartments where wire routing passes near exhaust manifolds or heated surfaces. Pre-formed wire construction ensures correct length and spark plug positioning without modification, eliminating fitment guesswork and reducing installation time. The 8mm diameter wire diameter and quality terminal connections provide robust conductivity and long service life compared to standard replacements.

This plug wire set is ideal for street rod builders, performance enthusiasts, and engine rebuilders working with 350, 383, or other small-block Chevy mills equipped with HEI ignition systems mounted above the valve covers. Over-the-valve-cover HEI distributors are common in tight-hood installations, custom engine bays, and modern fuel-injection retrofits where distributor accessibility and air-flow management take priority. Proper wire routing is essential to prevent cross-firing, signal degradation, and spark plug fouling. The pre-bent configuration included in this Moroso set ensures correct wire paths and reliable ignition performance across the entire RPM range, making it the go-to choice for comprehensive ignition system upgrades.