This system features an amazing ignition module capable of producing up to 20 amps to drive an all-new coil that can deliver more than 150 millijoules of energy. To handle this power and the larger coil, MSD designed a special cap and rotor made from DuPont Rynite. 

Additional features include an adjustable rev limiter, built-in Traction Control Detection technology and an independent tach lead. 

The Extreme cap will fit a stock HEI distributor, but must be used with an Extreme Output Coil Cover and Extreme HEI Rotor (sold separately). Kit show in picture This part is cap only.