New VR for Pertronix III?

I have the same system in my 69 dart .. and i kept on going through voltage regulators .... i ended up buying EI regulator for 20 dollars ... BUT they would not last... then i got the info from here to buy the better one from NAPA ... i think it cost me like 60-70 dollars and never had an issue since ... Do a search for EI voltage regulators and i am sure that you will get your answer...