Yeah, the MSD has 400 volts! Hooked in parallel to two coils, it's still 400 volts, but half the available amps = not as good (cooler weaker sparks etc). Hooked in series, the amps go back up to where they should be, but the voltage is halved down to 200. That's weak! You need at least 400 volts in the primary windings to get good results out of an MSD because it drives the coil like a step up transformer; bypassing the whole kettering effect.

Now imagine that on a smaller scale with a single HEI. Yeah, get two.

 

So where does the MSD go? LOL!!!!! Hook up a FC coil or any DIS coil and those issues disappear... 400V and all the amps!!!