That is a vacuum leak or intake sound if I ever heard one. (some carbs can whistle)
Listen how the tone changes with throttle opening, and goes away at WOT.
You are correct. It's coming from the carb. I sprayed carb cleaner evetwhere and it didn't change. Can't get it to do it as bad while under the hood but it's definitely coming from the carb.
Any ideas on what could be done?
750 Holley street hp with phenolic 1" 4 hole spacer.