Are you running them with both working at the same time, one to one linkage, or with progressive linkage?
You probably need to lean down the metering rods on the primary step, the bigger step up high, to get it to run good at light part throttle cruise
I would adjust the primary idle mixture screws so it is as lean as possible and still start and idle okay with no stumble from driving away from a idle.
What spark plugs brand and part numbers are you using now and how much compression on your motor?
The new Eddy carbs are not as good as they use to be
You can get them to work excellent with enough tuning, so good they should knock the tires off at will at WOT