In all the Crane ignitions, they want you to place a capacitor in line on the 12V and ground lines to the ignition box. They said to protect angainst spikes and surges.
They supplied a Mallory unit that claimed to protect up to 20V. (I must have exceeded that on the charger

)
MSD, according to their Tech line also suggests the capacitor, but they label it as a Radio noise suppressor. It looks just like the mallory unit but red. Tech told me it is also for spikes and surges but the instructions that come with it don't mention that at all.
I installed it even though I can't hear the radio while running. Does everyone following this thread use these?