I'm going to throw in my experience using the Mallory Electronic dizzy from Patricks. One thing that it does like is a bit more base advance that one with a vacuum advance on it. I'm running 15 degrees btdc, rather than the o degree setting of the stock dizzy. Otherwise, it will want to stall at idle speeds, especially coming back to idle from open throttle. Another issue, use of an ignition control box (I'm using a 3LRi myself) improves the performance greatly on these distributors, especially if you're going to use a hotter coil. Seems with the hot coil run through a ballast as shown in the directions cuts the voltage too low to get a solid spark. The box eliminates the ballast, and controls primary voltage based on engine rpm. This setup is working very well for me.
The only issues I've had with my Mallory, other than tinkering with the timing to get it to run smooth at idle, was that the center contact in the cap self destructed. Not sure what happened there, but I haven't had any problems since the new cap was installed.
