At the risk of feeding the fire (and because I have a genuine interest in the topic) I switched to HEI when I first worked on the car. I had done a tune-up previously but the car was still acting funny, so I switched to a Blaster 2 and widened the plug gaps (I was already running MSD wires).

I can't say if it made a huge difference in performance as the car was still acting funny but it certainly helped it start faster. Combined with a new starter, the car usually fires before it even turns over a full revolution. Even with the old starter, the ignition improvement significantly shortened the number of turns before the engine caught.

I am running an MSD-specific ballast resistor instead of the factory setup, as the datasheet for my coil specified using it if there was a resistor in the car originally.