AllTheGearNoIdea, your bench psu is grossly overloaded. That MSD box pulls 36 amps peak through the thick battery feed wires. Put 50,000uF across the supply line. When you are single pulsing triggering it at the start it should give a ~1kHz chirp, not the lame noise it actually made.
Rant mode on/
I have been making ignitions since 1977 and fiddling with (mostly repairing) MSD ignition boxes since 1981. IMHO they are a great steaming pile of doggie-doo. The advertising dept of MSD are provably and measurably flat out liars. They claim for that box 100mJ spark energy. Certainly the box puts out 100mJ but a great deal of that energy is channeled through a clamp diode back in to battery positive. That, combined with coil losses means that with a good E-core coil you only get typically 35mJ out of the secondary, and if you use an old fashioned points coil you only get 25mJ out of the secondary. The duty cycle of the secondary current when multi-sparking is advertised at ~40% according to the brochure, but in truth is it about 12.5%.
Rant mode off/
My discussion on an ECU hacking forum ->
https://pcmhacking.net/forums/viewtopic.php?f=22&t=3364and with some (but not all...) *very* smart engine-smart guys ->
http://speedtalk.com/forum/viewtopic.php?f=1&t=42274