MSD Digital E-Curve distributors will drop right into your engine and fire up with three simple connections! Not only are there no external controls or boxes to mount and connect, but you can set a timing curve with the twist of a rotary dial! That's right, no more springs or stop bushings to fumble with. A new digital module lets you select from 20 different "centrifugal" curves and five vacuum curves--that's 100 combinations! Simply remove the cap to access the rotary dials and select a curve to match your application. You can also set an rpm limit that will protect your engine from over-rev damage caused by a missed shift or driveline failure.