Gents
Hopefully, this isn't too dumb a question.
I'm trying to figure out how to adjust the idle jets (screws) on 2 4bbl carbs on an open plenum manifold?
Carbs are fine otherwise, and they run well. It's just the off-idle response is a bit rough.
Because it's an open plenum manifold, I can't seem to detect any change in vacuum signal.
Maybe it's just my approach, but thought maybe some of you experienced guys might offer a solution.

Thanks 
Jim