1966 Plymouth Barracuda Help!

Bought the Cuda from my brother as a first car. it Has a 318 v8 in it. I need help or any sort of advice to fix 2 major problems with it. First i was wondering why my ignition coil wont get any spark. it was before and now i recently replaced with a new coil and now i have no spark. i Can provide how i have my coil wiring hooked up if needed.
Secondly when it was running before it had an overheating problem. So i went out and got a new thermostat and had my radiator flushed. Replaced my water pump gasket. Seemed like it wouldn't overheat to bad at idle but as soon as i put it in gear(Automatic) and drive or put any power to the motor it'd overheat ending with the water in my radiator boiling hot. ANY ADVICE OR HELP MUCH APPRECIATED. I've ran out of options and im stumped.