75 duster slant six weak spark

UPDATE. The car starts and runs.

Got a packard 56 connector from NAPA (85 cents) for the brown coil + wire, cleaned the firewall connectors with brake cleaner (didn't have electrical cleaner) and got all that buttoned back up including filling the female connectors with dielectric grease.

I didn't check the coil ohms as suggested above. Not sure why I didn't.

Also cleaned the other packard connector on the passenger side inner fender (had some old stale grease on it but no corrosion that I could see). A quick buzz with a hand file till it was bright shiny brass and back together it went.

STILL wouldn't start, although it wanted to during cranking. Strangely as soon as I let go of the key, it would die which as we all know (or should know) is the ballast resistor. I had just purchased it a month ago and the car had not yet run on it so I assumed new=good. It even tested out within specs on the ohms but as stated above, the pins seemed flipped around. I even connected it upside down but still no dice. It was 12-15 dollars at AutoZone.

Scabbed the other ballast resistor I had on my 73 Duster out back. I'm so glad I left that on the firewall when I pulled the motor 10 years ago. Once I installed that, it started right up.

I'm going to get a new cap and rotor because it has a few single misfires when accelerating. Timing is 5 degrees BDC at idle. Plugs gapped at .035
Found that the black w/ green tracer to feed the negative coil post had some shitty connection done by previous owner. Seems to work for now, but will do it right when I can.
I also installed a brand new ground cable since I found the old one was starting to grow green under the insulation down by the engine block.
If I don't buy another Crane PS-91 coil, I'm going to HEI it as I've heard alot of good things about that conversion.

Thanks to all who helped with this. I understand a ton more about the ignition system, bulkhead connectors, and voltage drops now. Awesome.