Great analysis Mike. I learned, as we all have, never say "always" and "never" when it comes to Chrysler components. There was also a late 7O model year parts counter replacement for the 3438172. It's the "389" that is listed by Morty above. You will see NOS examples pop up for sale from time to time and they are usually dated for late 1970 through 71 production vehicles. They were 37 amp alternators. I have also come across a couple of "537" single field alternators dated late 69 (oct/nov). I assumed they were put together from the "spares" bins and sent to the dealers as replacements for the 66-69 model vehicles.