I have a 70 GTO I have been working on and have been trouble shooting electrical problems. The issue I have is no power to the distributor coil when I turn the key to the on position, the car will crank but no spark. When I turn the ignition to the off position it will give a spark. So if I...

just rebuilt my 4l60 new converter and trans cooler. Got to temp and lost 1st and 4th took it back and the battery voltage was low. Tried new + terminal and nothing. Any ideas on what could it be? Trans is coming off and getting looked at to make sure everything is good.