MSD II ignition coil installed, now timing is whacky

I have had a pertronix installed for over a year. Yesterday i installed a MSD II coil, with a ballast, but now my timing is whacky. I have had it set to 6 degrees before but with the MSD coil it wouldn't stay running at 6. It didn't seem to run happy until around 18-20...but i don't know for sure because it was WAY off the scale. I didn't feel comfortable running it with the timing off the charts like that so I want to get some advice.
Even with an MSD, should it be set to 6 degrees? if so, where should I begin troubleshooting if I cant keep it running at 6 degrees?

Hi, so did you just change out a Pertronix coil, and install an MSD, or was more work involved? One issue could be that the Pertronics runs on 12 volts, and a ballast resistor will lower the voltage the Pertronics gets. That much timing adjustment is strange. A lot of the engines like more timing for improved performance, but it should run the same with a coil swap if the parts are meant to work together. Good luck

Hi, thanks for the reply. I was running the stock coil and swapped it out for the MSD. At first, without a ballast, it wouldnt even turn over. With the ballast I was able to get it started but that when I ran into the timing issue described at the top. To be clear, the pertronix im using is the kind that drops in to the stock distributor.

Stock timing for an automatic was 12*. I'm running something in the 20* static timing range now. I think I was running roughly 15* before wsa111 recurved my distributor for me. The car has been running like a raped ape ever since he dialed the distributor in for me.

Have you tried re-installing the stock coil to see if it performs the way it did before the coil change?
Just to be sure something else didn't coincidentally go bad at the same time of the coil change.