Runs a bit lean...

After the head rebuild, I the slant in for a bit of professional maintenance. Timing was dialed in, compression (although I don't have the numbers from the test) came back in good health, and a tune-up was made. Something the matter, though, is that the carb (an early Holley 1920) is acting up. I rebuilt it a few years ago and it was running just fine before. It had a mild idle that occasionally had a hitch somewhere, but it ran well. Now, it doesn't want to hold idle and its running lean. I've rebuilt it again to make sure there wasn't something wrong internally. I have more adjustment response now that I have done it, but it idles better with my hand restricting half the airflow. Is this a choke issue of some sort? I went ahead and bought the electronic choke that is a popular upgrade, I've replaced the fuel line from fuel pump to carb and a new filter was installed. Still struggling to hold idle in park, much less idle in-gear at a stop light. Any ideas, maybe?