Frank,
Good question. I just waded through the Rochester B book, and my unprofessional opinion is that it won't affect the idle of the engine.
This assumes we are talking about a slightly out of adjustment float. On the model B, It looks like the system takes fuel from the
bottom of the bowl, through a jet for final mixing for the idle circuit.
My bet is that 'carbking' will see this post and blow me right smack dab out of the water....we shall see. I have my life vest on!
Stuart