It seems the Pertronix is VERY susceptible to having a catastrophic meltdown if the ignition switch is left on for a few minutes without the engine running. The parts are also proprietary to that system, and aren't available readily at local parts stores. Points can burn under an "ignition on- - -engine off" situation- - - -or not- - - -depending on whether the engine happens to stop with the points open or closed. It's almost a guaranteed disaster with a Pertronix. If you want an electronic ignition system, the OEM General Motors HEI distributor for a 250 6 cylinder is almost a drop-in fit, and parts for it are available everywhere.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!