70 Duster runs rough or dies when up to operating temps

you have 7 volts to the coil, I would say you got the ballast wired correctly. I have seen that at higher RPM the voltage to the coil increases but I'm not sure it ever reaches 12V

  1. Your 12V source to the orange box comes from the correct cir? 12 V in Run / Start not after the ballast resister?
  2. Orange box is well grounded?
  3. Do you have another to swap in to see if that is the issue?
  4. The reluctor gap is correct?
  5. the carb is adjusted correctly?
  6. the choke is opening when at temp?
  7. there have been reports of distributer wires from the pickup being reversed and making a difference ( I still don't know how that works) but you could get 2 trailer light pigtails and make a polarity switched connector
upload_2022-5-22_19-36-45.png


OR it might be as simple as you need to tune it to idle when hot rather than cold. Choke will take care of that for you.