The 1970 models got the electronic regulator.
I've had an alternator on the car that charges fine except when the A/C fan is on, headlights and low rpms. The day the ECM failed, I don't know what the battery voltage was when I left the house. It may have been lower than ideal. When it stalled and shut down, it seemed to crank slower and slower in a short amount of time like the battery wasn't anywhere near a full charge. I tested it before I went back for the trailer..I was at 12.01 amps. A couple of years ago I was amazed to learn of what is considered a
fully charged battery. See the chart:
View attachment 1716315417
In short, each tenth of an amp is approximately 10%. It still boggles my mind.
I tried cranking each time I tried something new...Wire connections on the ballast, coil, distributor, change the ballast, change the ECM...by then it would barely spin over. At home I added a jumper pack to the battery and I swapped in a generic ECM...
View attachment 1716315418
It started and ran fine. A couple weeks later, it crapped out. It seems like something in this car shortens the life of these ECMs.