Quick Question Coil issue or more? (Mopar but not A-body)

If the coil & ECU have the correct voltage while you are cranking, then the problem is the coil or ECU. Assuming any plug/connectors in the circuit have been checked for corrosion, proper connection.

Coils can measure ok [ resistance ] & still be faulty. Substitute is the only way to check for sure & same with ECU.