So, the "pop": was it a backfire from the tailpipes, or from the carb, or somewhere else?
If it was from the carb, I'd certainly check the PV, but I wouldn't expect it from an exhaust backfire.
I can't imagine a backfire either from carb or exhaust to CAUSE valvetrain damage.
In the old days, you could tell an exhaust valve was bad by a sustained light popping through the exhaust; engine would run, electrical would be unaffected.
Popping/backfiring could be a symptom of a valvetrain problem as opposed to a cause, doesn't seem like that's your problem.
Never had a scenario where an engine malfunction would kill the electrical system; I'm guessing something electrical is the root problem.
You're gonna need to check a few things out, and report back.