72 C20 Dies, Very Intermitent

[ajsfirehawk]

72 C20 350 automatic. HEI distributor. New bug just cropped up last weekend, driving along, purring like a kitten at about 50 mph. Instantly it dies, no spark, just like I turned the ignition key off. Rolls to a stop, I turn the key to try and start it, nothing. Starter relay doesn't even pick, nada. I snoop around under the hood, nothing seems out of order. 10 minutes later it fires up like nothing happened, drove it 70 miles home.
Same scenario happened again Saturday. I pull apart the distributor, noticed a small crack in the top of the cap. Pulled the ICM and the heat sink paste only covered about 1/3 of the control module. Bought new, swapped them both after carefully labeling plugs wires. Happened again this morning. I'm starting to think it may be in the ignition switch. I did shoot some lock lubricant into the door locks AND the ignition switch about a month ago. Is is possible the lock lube is causing issues with the contacts inside the ignition switch? Other thoughts.
Next step for me is to buzz out the entire ignition circuit point to point. NOT looking forward to that exercise.