As said, AFB jets will be nowhere near to the Holley jets. If you have 89's in the front, it will be way rich on the primaries. What is your Holley list number? Looks like a starting point on my jetting would be about 62 X 66 and tune from there. It is on the back burner now-moving on.
I would not be running this engine at idle a whole lot. It sounds like you cannot really drive it properly; the ring seating will not be complete until you can 'load' the engine some and put some real compression pressure on the rings. Time to stop playing with the motor and work on getting it on the road. As said, you can't really know where the carb is tuned by just idling. I agree, I put the engine together myself in January and I have been trying to get it running somewhere in my comfort zone so I can finish up the engine bay and put the rest of the car together.
And as for your vacuum levels, I agree that you could have significantly higher vacuum levels. At some point, you are going to have to start adjusting the secondary stop screw, and then work on the PCV operation. Both of these effect the 'excess air' that is let into the intake at idle.
