I'm not running a vacuum advance either. I went through pretty much the same situation, tried carburation, which was another problem althoghether, checking the valves, coil issues, the whole enchilada. My dad just happened to get a call fom my uncle, who has been messing with these things since the mid-50s. He's the one who told me to try advancing the timing. I just advanced it a little at a time, about 5 degrees, until it sounded happy. I actually drove it at 10 for a while, then tried 15 on whim. Mine likes it better at 15. I did also find that the electronic dizzy works better if you eliminate the ballast and run a spark control box, like the Mallory 3RLi. The dizzy seems to work better getting 12 volts to the electronics.
