The PN 8728 can be installed on engines with a GM HEI Ignition, Ford or Chrysler electronic ignition, any standard breaker points systems or even with an MSD 5 or Blaster Ignition (non-CD ignitions). The Soft Touch Rev Control is adjusted with plug-in modules and is supplied with 6,000, 7,000 and 8,000 rpm modules. When the engine reaches your set rpm, the Soft Touch circuitry kicks in and drops the spark to certain cylinders. This limiter produces very accurate and smooth, backfire-free rev limits. Can be used on 4, 6 or 8-cylinder engines with inductive ignitions.