NO spark question

So in my 68 340 dart I had an electrical failure, car just shut off. I've changed ignition switch,voltage reg, ecu, and coil swapped with a working one. I know new doesn't always mean good but... I'm getting 12.5 v at the battery with the y off and 12.5 at the starter relay with the key off. when i turn the key i get 12.1 at the starter relay, 11.6 at the voltage reg, and11.2 at the coil. I had someone crank it over and voltage dropped to 8.9 at the coil. but no spark coming out of the coil?? Any thoughts??

thanks