Switched Coil now it wont start. 1972 Swinger 318

Dart was running fine up until I decided to put a HP coil from accel. Made the switch and the engine would turn over but not fire. Pulled the plugs and I have no spark. Swapped the old coil back in and same situation still no spark. :banghead: Anyone have an idea of what could cause this? Car has a Mopar orange box ignition.
Thanks in advance!