Ignition planning/understanding
You might want to read the technical discussion on this website,
www.worldphaco.net.
He compares CD ign [ MSD & other 6 boxes ] with inductive ign. The GM HEI inductive ign pretty much levelled the playing field & is hard to beat except for an all out competition engine.
Think about why GM style HEI dists are now available for non-GM engines.......