I never use the vacuum on the distributor I had in there. I just purchased a new distributor this morning that has full adjustments for the curve the limitation and the vacuum advance which I probably won't use again...
The distributor I have or I should say had a dissected and there's no way of really adjusting things. I just left it apart and ordered a new one..
It was just cheap Chinese junk to begin with so I'm not worried about it and could have been part of my problem...