Use with Pro 600 Ignition - Coil-Per-Cylinder Engines;Designed for extreme racing for the Pro 600 Capacitive Discharge Ignition, PN 8000; Capable of up to 50,000 Volts to ignite extreme cylinder pressures; Over 200 millijoules of spark energy makes them ideal for use with methanol, ethanol, E85 and forced induction and power adder combinations; Supplied with hardware to mount horizontal or vertical position; Coils are designed to be mounted on Holley’s LS valve covers, or Original Equipment LS passenger car coil brackets using 72mm bolt spacing; HEI style secondary tower for secure coil wire connection;