ACCEL HEI Super-Coils are a direct performance replacement for stock units. They feature highly specialized silicone-magnetic steel cores that, together with these coils' optimized winding resistance and turns ratios, deliver 10-15 percent more energy than Original Equipment Manufacturer coils. Specialized high-temperature epoxy resists shock and vibration and still increases thermal conductivity. Engineered for Buick V6s and V8s and Oldsmobile and Pontiac V8s, ACCEL HEI Super-Coils are compatible with HEI ignitions and later-model computer-controlled systems.