Dual Magnetic Dizzy Mopar Perf P4876735

As I recall:

NASCAR and other endurance ran Dual Pickups
and ignition boxes that in case of a problem could
be switched from the drivers compartment without
stopping the car.

In most engines that are moderate enough to be street
driven for periods of time (Even in the many of bracket cars)
I have found No advantage in performance in running a MSD 7
over a MSD 6. That also includes all the "new improved' digital
controls over the older analog units. Also, I only get a year or two out
of the digital units before problems. The old analog units often run trouble
free for 10 or 20 years. They are what is on my dozen race cars our family
utilizes.