HEI conversion question

That box mount is just to keep the stock look. Not important for me since my 1965 Dart had points. I used the later 8-pin HEI module w/ GM coil, which is much easier wiring since a GM cable connects the two and it uses quality sealed connectors (Metripak). TrailBeast here sells it kitted, otherwise take from a junkyard 85-95 GM pickup. To insure pickup polarity, wire temp w/ wire nuts and spin the distributor by hand, with the coil HV lead going to a test spark plug (or the end held near an engine ground). Clamp a timing lamp over the HV lead and shine at the distributor reluctor teeth. If the teeth align with the pickup (when sparking), you have the polarity correct. If the pickup is in-between reluctor teeth, you have the pickup wires reversed. The later will still spark, but will be erratic in time.