[Tongue Pirate]

What size is your carb? The symptoms you suggest indicate that you aren't getting enough fuel down in there when you "hit it". .30may be a good starting point. My 289, when I had the holley on it, a 600 DP, ran perfect with a primary nozzle of .25
-Are all of your unused vaccum lines plugged off?
-May seem odd but did you try going down a size or two on the Primary nozzle?
-Using the carb size calculator (displacement x rpm)/3,456 if you are planning on spinning 7000rpm you could go up to an 850 carb, at 6000rpm you could run 750. For street smaller is always better & throttle response tighter.

I rebuilt a holley at one point & put it on a motor. It ran poorly for a few days on the lower end. About the third day what ever was in one of the passages must have worked it's way out cause it just all of a sudden ran perfectly. Small particlles of dirt can cause a lot of grief. The other part of this story was that this was another 600 DP & it was on a Built Big Block Chevy motor. The car had pretty tall gears so 4500 rpm was probably all I needed out of it but that carb ran so well on that motor. Much tighter than the 750 & 850 before.