The more I learn about Pertronix, the better I like the GM HEI system! (Thanks, Jon!) GM uses a magnet that surrounds the pickup coil, instead of a rotating magnet. The trigger on the distributor shaft is a simple piece of steel with as many triangular points on it as the number of cylinders. The dirty little secret is that there can be half as many trigger points and the system works as well, if not better since there are still the same number of corresponding trigger points on the pickup coil core. In other words, three points on the rotating shaft and six on the pickup will still fire six cylinders- - - -there's just half as much induced voltage going to the module. That's why my modified HEI distributors on the race engines would wind 1000+ RPM faster than the competition without getting spark scatter- - - -I ground half the points off the rotating trigger! The tech inspectors were too dumb to catch that little modification on a "street stock" engine, along with a couple of other Smokey Yunick type tricks I used.
Jerry
