Want to improve ignition....

All that pertronix ignitor stuff used to fail in about a year or so, I don't recommend that crap to anybody. I always like to use m s d stuff or just the factory Orange Box and distributor with some shortening of the Curve and Advance rate.
One thing's for sure the most important things to consider are what plug wires you are using, their resistance, and a good hot Spark from a good coil. With that said ... get good plug wires with no more than 5 or 600 ohms of resistance and buy a hot coil...because It won't matter what you have for ignition if you lose half the energy through the spark plug wire.