79 300 no run?

i have a 79 chrysler 300 (cordoba, yes i know not an a body) i was driving down the road and started having some obvious electrical issues, the headlights went dim and started missing like crazy and just quit driving down the road, after countless hours now trying to figure out whats wrong im ready to give up, so heres what happens, it seems to have power while cranking because the car will fire, once you let the key into the run position it seems to lose power and then quits. now the car was a lean burn car, the previous owner converted it over to a regular electronic ignition system and car now uses a mopar orange box, i have tried numerous ballast resistors and helped nothing, we were able to trick it to run by directly powering the coil and it would run, unfortunatly now when cranking it wont even fire so i've managed nothing but make it worse, any ideas??? i can try and provide more info if needed, thanks guys