thanks to storm "sandy ******" all my tech lines are closed here at work. the original ballast for a 65 is an ICR12, my books and compy dont tell me resistance ratings and no stores around have one to pull and test....but for a factory electronic ignition system chrysler used a 1.2 ohm ballast.
for a single circuit ballast thats 1.2 ohms is an ICR23. the dual circuit version is an ICR24, with one side at 1.2 ohms and the other at roughly 5 ohms.