Engine died. Now won't start

Was slowing for a stop light the other day and the car died. Pushed it to the side of the road and tried restarting it. Nothing. Waited 20 minutes and tried again. It started then died 5 blocks away. After towing it home and checking for spark, nothing. No spark out of the coil to the distributor. Replaced the ECU with one I already had, nothing. Did notice that the ballast gets really hot with the key in the run position and replaced it with another one I already had, but nothing. '73 Plymouth Duster with a 360. Replaced Accel Superstock coil. The coil has no resistance between pos. and neg. terminals, and has some resistance from the terminal to the tower using the ohm meter. The car had been running very rich and I was checking the run characteristics for timing advance when it died. Made the Ammeter bypass conversion a month back but that was straight forward and hasn't been a problem. Any suggestions or things to check would be appreciated.

David