hesitation at part throttle

Having a hesitation/stumbling issue with my Dart and looking for some help. 67 Dart,360 w/ ld340 intake and 600 performer carb. My car starts normally and idles ok. It has a hesitation /stumble almost like a miss at part throttle or cruising speed. Kinda clears up when you step on it. I have replaced my spark plugs and wires. distributor cap and rotor. Did a compression check(all between 115-100),checked for vacuum leaks around carb base and intake(found none). When car is idling I hear a loud air noise coming from the secondaries on the passenger side. Sounds louder than I remember hearing before. Is it possible that something is amiss in the carb? I did install a new edelbrock inline fuel filter as well. It is very annoying while cruising and i am running out of things to check. I hate to spend another $300 on a carb if it is not the issue. thanks