Pertronix has been around for a LONG time, converting points ignition to electronic before the manufacturers ever did.
Early models used an optical system with a light and pick up and a breaker wheel (very similar to the guts of an old mouse) new uses a hall effect pick up.
I used one of the early models on my VW dunebuggy WAY back when. worked well.
Few weeks ago I ran into an issue with a set up that had been installed on a forklift. stock ignitor died, they bought a Pertronix to replace it (cheaper) .
They could not get the engine to run, and my company sent me to check it out.
I found that I could get it to run if I retarded the timing all the way to stop and disconnected the vacuum advance, but it wouldn't run well. tried to move distributor one tooth either way wouldn't run at all then, ????
Took the parts out and looked at them close, then I noticed the relationship of the flat on the dizzy to the magnets on the ring supplied with the Pertronix unit.
For a 4cyl, the magnets are spaced every 90*, and these infact were, BUT, the the magnet circle was turned 45* from the flat of the dizzy causing the timing to be VERY late or WAY too early thus not letting the engine fire.
Asking the owner of the machine for the original parts, ( which, smartly he had kept) I verified this with the stock magnet ring, sure enough, the magnets were inline with the dizzy flat.
Not wanting to chance the same problem with another Pertronix set (could have been a misbox, or production mistake) I ordered the proper factory ignitor ($$$) , truck runs fine, better than it had in years accoring to the guy that drives it.
Something to keep in mind when dealing with aftermarket parts, they aren't always perfect.
I replaced with a accel piece and have loved my ignition ever since
