Any part can go bad prematurely, I would seriously look at the coil especially if you haven't been running the ballast. The ballast takes over after start to lower the voltage to the ignition system. With no ballast it has been running at full voltage constantly, unless there is a specific reason the ballast has been deleted. I'm certainly no "expert" but I can speak from experiences from owning a lot of Chrysler products in the past 35 years.
