Which is just as well, because the orange box ECU they come with is Chinese garbage and the distributor they come with has an advance "curve" (more like a straight line) totally unsuitable for street use.
Not me. Use GM HEI parts (they work better) or use Chrysler parts (they work OK as long as you buy a good ECU) and you wind up with a system that can be easily, quickly repaired in the event of a failure, with parts available in every nook and cranny of North America. Use Pertronix and you're outta luck when it fails until the company can ship you some repair parts.