Spark Plug Wires: To prevent false triggering and the possibility of premature ignition failures, use suppression type spark plug wire. We recommend spiral core ignition wire, such as ACCEL 8mm Spiral Core SuperStock, ACCEL 8.8mm Spiral Core, ACCEL 300+ RaceWire or ACCEL 8mm Extreme 9000 Ignition Wire. Do NOT use a copper core