I personally did not find much of difference between the stock coil and the Blaster II using the stock ignition set-up. The big upgrade was when I switched to the Permatune with their recomended coil......car seemed much more responsive. At the same time I did rebuild and synch the carbs so I really couldn't say how much was exactly related to the ignition upgrade.
Just my opinion....others my have had a different experience.

Frank
83 Jalpa