Brad - How about this? When the engine is dry but cool, take a spray bottle and wet one component at a time until the engine refuses to start. Also, look at your engine in the dark, what you see might be instructive.

It would be far easier to assess one component at a time than to hope to find the offender among many possibilities.

I would suspect the coil wiring, coil wire, power stage, suppression relays, or crankshaft sensor.

Look at the FAQs to make up a list of suspects.

Your problem could even be as far away as the fuel pump.

The cover on the distributor might be for water, but my old-timer advisor tells me to discard it after it gets dirty because it hides dirt that can cause arcing.
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3 8s & 2 7s 725,000 miles total