Edelbrock carb tuning Q???

have an edelbrock 650 on a sbc 305 (too much I know)...when adjusting the idle mixture screws nothing changes on the vacuum gauge and I can run them all the way in and nothing changes (don't know if I tried running them in at the same time but one at a time and nothing changes)
Whats going on??? thanks-

 

is your idle speed set above 1000rpm? If so its rinning off the venturis and not the idle circuit. May also be a vacuum leak as well.

 

Are you reading from ported vacuum or full manifold vacuum? What kind of vacuum readings are you seeing?

 

vacuum advance is unplugged...
vacuum gauge is connected on the lower right hand vacuum bib on the carb...
idle is too high, will definitely lower it and check again...
seem to remember the readings were around 16-17...