Maybe more confirmation than a question.

78 Magnum, 318-2, leanburn converted: Lately it randomly won't start, I only have to turn the key off and back on, usually by the 3rd try it'll start, and it's not every time I drive it. I have noticed at times the engine "jumps" or seems to fire when I turn the switch off. I seem to recall that meant the pickup coil was going bad. Wonder if maybe the ICU may be the culprit? To date it's not left me set. Yet

Could be either, lately I had a slant six doing that and seemed like if I got it rolling over it would go as soon as I let off the key which to me meant the start side had went away so put the original box back on and was back to normal. That was an orange box that went bad and had a place on the back side where you could see it had heated up and left a burn mark

I'll take it off and inspect it. Thanks

Yes, if you have a another box maybe try it.

I would be suspecting the ignition switch

My Barracuda did that when the bulkhead connector failed on the start wire from the ignition switch.

another area to inspect is the steering column connection to the harness.
i have seen, and repaired, many over the years. that connection becomes corroded or loose, then arcs and burns/heats the connection, sometimes melting the connector block.

Swapped out what appears to have been a repo box and installed one that is a Chrysler unit ( supposedly ).

Seems to run different (not so much better just different) but starts better all the time. We'll see.