The mid 1980s were the beginning of the end for distributors in regard to new cars. The Buick Grand Nationals started using coil pack technology while many other GM vehicles were using dual tower coil packs sometimes known as Waste Spark systems. When Ford moved to the 4.6L Modular engine in the '96 Mustang, there were two coil packs with four towers each set up as a Waste Spark. Other common applications came from Mitsubishi and eventually Chrysler systems. MSD's DIS-4 Ignition Control is designed for engines with coil pack, waste spark ignition systems and is capable of firing up to four coil packs (or even four individual coils). Each Control delivers full power Capacitive Discharge sparks from idle through racing rpm. Below 3,000 rpm there is a series of multiple sparks that last for up to 20° of crankshaft rotation to improve idle, starting and throttle response. The adjustable features of the DIS Ignition includes an over-rev limiter and the holeshot rev limit. Also, there is a step retard that can be wired directly to a nitrous system or switch for activation! These are adjustable with rotary dials. For use on 6 or 8-cylinder engines with two, three or four coil packs.