Thanks for the info.
So if I understand right, the MSD and the HEI are exclusive. Either one or the other?
I am glad you responded. I have followed your HEI discussions.
Yup, that's pretty much it.
HEI is what controls the spark, and the MSD is what controls the spark. (both just high speed switches)
The coils are what put out the spark they are capable of.
There are differences though, between the two in area's like MSD's multispark at lower RPM's and the HEI only one spark per cylinder fire, and the obvious design and marketing differences.
Myself, I don't care if my ignition system has a name printed on it or not as long as it does the job reliably and inexpensively.
