Idle drop by 500 rpm?

When she popped outta the Primaries yesterday, even though the Carb has alleged " blowout protection " could that pop a power valve, And would that cause a vacuum leak?
No. you can take the PV out and throw it in the ditch and it will not affect idle. POWER valve. It's on the POWER circuit. Not the idle circuit.

I tried to point out that it sounded like a vacuum leak and advised you to inspect for such many posts ago. I'm backin out of this, because now you're going in so many directions, I'm not sure you'll ever get it right.