I have a Holley 750 do on my 425 and it quit running the other day acting like it was flooded. I tore the float bowls off and found a screw that had wiggled out of the metering block and on the other float I found a little plastic piece that I have never seen. I have no idea what it is or where it’s supposed to go. Bellow I will attach a photo in hopes that someone can help me identify it. Thanks

 

See following diagram (part # 117: "Metering Body Vent Baffle") : Holley exploded view

 

I can see that curly dog hair causing issues...