Need some Holley experts to ID this

I had my 4779 750 out and working with it in my parts washer to swap on a 750 HP main body.

When I was done, I saw this little screw on the shelf. IT MAY NOT BE FROM THE CARB... but it probably is, given I had just been working with it right there.

It has a flat head screw slot in the top of it, and a very tiny orfice through the center of it. I cannot find any place on the carb where it seems to have come from, and both of my Holley books don;'t seem to make reference to it. It's not a high speed air bleed jet.

Or if anyone can confirm that they know Holley's so well and they are confident that is NOT to the carb, that would be helpful too. THanks
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