Carb Tuning / Vacuum Problems?

Shouldn't be too many miles on the engine. Guy I bought it from claimed to have just rebuilt it but who knows. I've put about 2000 on it since I got it.

Hard for me to say if this has happened gradually. When I first got it, there was a thermoquad on there. It stumbled under hard throttle and I had problems getting it to start when warm, especially if it was warm but not hot. I also played with timing at some point there without a timing light, which probably wasn't too smart. It kept giving me trouble starting and the TQ looked like it needed a rebuild so I bought a new Holley since it seemed better for a newbie. With the Holley on it starts great but has the current problems I'm dealing with. Sorry I can't be more specific but I didn't know as much when I got the car as I do now so I can't really describe the symptoms.