Thank you for the suggestions.
My 1977 is points ignition. The plug boots had an off spec resistance and were replaced.
Update: I installed a brand new OEM replica coil moments ago, replacing the one serving the back cylinders, assuming it to be the offending component. The old one did not seem to be cracked or damaged. I've checked each side for spark which it has.
I now seem to have my coils wired in incorrectly. My engine now will not turnover and gives the occasional back fire.
My coil to cylinder setup is as follows:
Right Coil (old):
Right lead to right-front cylinder #3.
Left lead to front left cylinder #4.
Left Coil (new):
Right lead to back-right cylinder #1.
Left lead to back-left cylinder #2.
I have the resistor attached to the right side with the black wire wired to the side of the resistor with black rubber on it. And the wire with the small brown sleeve attached to the side of the resistor with no rubber.
I seem to have taken a step backwards, are my coils wired wrong? I do have spark.
Thanks again. I have a lot of new ideas, but need to get back to my baseline now....