HA;

There is nothing electrically special about the armored cable other than it physically does not allow access to the 14 or 16ga wire within which connects from Ign Sw to Coil Primary...

If I understand function of the 123 correctly, it really only replaces the electromechanical "points" (which are subject to arc-erosion/wear) with a solid state transistor not subject to any kind of wear like that...so unlike the points, the 123 is basically forever!

Functionally, the Hall-effect trigger of the 123 still only results in ONE closure and opening of the primary current path, per cylinder, resulting in ONE High Voltage pulse (unlike Multiple Spark Discharge MSD systems)...point is, function of the Coil is absolutely unchanged and equal to points in every way, with the 123...Bottom Line: If coil had good output before installation of 123, it will continue to afterward!

Yes, Coil output can be measured, but this would require specialized equipment/knowledge/practices, so if you don't want to set up a high voltage lab, the next best thing is viewing/comparing spark across a constant gap (like a test spark plug). Difference between a wimpy little spark and miniature lightning storm will be pretty obvious.

I don't understand how Coil output can vary with age...copper doesn't change with age, neither does permeability of iron core...so if it works...it works! (intermittency notwithstanding).

"strong charge coming from the coil to work properly." I don't really know what that means and how to interpret it into info which can be applied to circuit function....if you could elaborate...

Cheers