carb question (Holley)

crackedback said
If that carb is less than about 20 years old, it should have the PV protection circuit in it.

I have cars that pull 7" of vacuum and have 10.5 power valves in them... If the idle is correct the PV isn't even in the circuit at all.

True but if it blows out then it is open all the time & would affect it at idle. Mine used to surge like an alcohol funny car at idle when it would blow.