Stubborn starting question...

Several issues here

First you MUST understand the tricks of Mopar ignition, which can lead you down the wrong road. That is, "IF" you check spark by the temptation.............of jumpering the starter relay while "under the hood," and checking spark, you have not set up "actual conditions."

The ignition switch is in reality several separate switches "in the same can."

Ignition "run" (IGN1) is ONLY present with key in run and NOT in start

The ONLY source of ignition voltage in "start" is the "bypass" circuit, or "IGN2". This is a brown wire, comes off the switch, goes through the bulkhead connector, and to the coil+ side of the ballast

So if the switch, the connector, or the bulkhead connector becomes corroded, you can lose that start voltage.

Next, is the distributor......points must be properly gapped, and if distributor is severely worn, points can become "not" opening or "not" closing because of shaft wear. The points themselves can be corroded to the point (no pun) that they do not conduct electricity. "Weird" problems like the wire feed through the dist. case can be internally broken or shorting to ground.

EASY to check the above.............

Clip your multimeter to the coil+, reach in and twist the key.......should be "same as battery" or 10V minimum

So far as points "not" opening or closing, best way is use a dwell meter "on the starter." You can also hook your multimeter or test lamp to coil neg. Meter should jump up/ down or light should bright dim "flash" as engine cranks.

Checking spark............. Because of the switch issue mentioned, you want to check spark USING THE KEY. So "rig" a test gap so you can see it, and crank using the key. Don't forget the coil wire........they can go bad internally.

Last is a tossup. You MUST have a good condenser (capacitor.) "New" does not mean "working."

And.......coils can fail. They can become intermittent, quitting when hot, or quit when they "feel" like it, or just quit.