Need help with lean stumble on Holley DP

I'm having the same issue. Do you have a vacuum gauge? On mine when I try to lean out the primary jets to get the cruise AFR correct, I get the same lean stumble. My problem is the car idles with 8-8.5 inches of vacuum, and I have a 6.5 power valve. At light throttle the vacuum only drops to about 10, and the power valve never opens, hence the lean stumble. If I use more throttle the vacuum drops below 6.5 and no problem.