MSD 6AL, PN 6420
The 6AL shares the same proven circuitry of the 6A with the addition of a built-in adjustable rev limiter. The combination of powerful sparks with the safety of a Soft Touch Rev Control is what makes the 6AL the most popular ignition control in the world.
MSD first developed the Soft Touch rev control to prevent overrev damage to your motor in the event of a missed shift or driveline failure. The rpm limit is adjustable in 100 rpm increments with MSD’s plug-in modules. When the engine reaches your selected limit, the Soft Touch circuitry begins dropping the spark to various cylinders. On the next cycle, these plugs are fired again to prevent fuel from loading up in the cylinder. The result is a smooth and accurate limiting action without backfires or roughness.
The Soft Touch Rev Control also opens the door for you to add rpm accessories such as a Two Step Rev Control. A Two Step allows you to set two rpm limits, one for a holeshot rpm and another for overrev protection.
The 6AL is supplied with rubber shock mounts and modules for 3,000, 6,000, 7,000 and 8,000 rpm.

MSD 6AL Ignition Control
w/Rev Limiter, 4, 6 (even-fire only) 8-Cylinder
PN 6420