Timing Question

I have 12 1/2° initial advance at 750 RPM. The vacuum is 16 1/2 mmHg at Idle. The timing runs out at about 2250 RPM and is right around 55° or full advance minus the vacuum advance. When I did use the vacuum advance it was plugged into ported vacuum. When I installed this distributor I found that it did not work with the vacuum advance as there was no change in the timing with the vacuum advanced canister. I found unhooking the ballast resistor and running straight 12 V to the coil the car runs much better ,I do have a high-performance coil.