ACCEL 8123 Cap and Rotor Kits create an impenetrable barrier to arc-through and crossfire. Specially designed to combat the severe demands placed on high-output ignition systems in GM V8 engines, these black HEI Coil-in-Cap style distributor caps guard against the high temperatures and surges of spark current that can melt molded components in OE caps. Made from a high-performance 60kV-rated alkyd compound, theyre stress-relieved immediately after molding to ensure dimensional stability. Highly conductive, corrosion-resistant brass inserts and stainless-steel rotor springs allow unrestricted spark-energy flow.