72 Duster, 360, not firing or starting

If you have a test light, the red wire you have on the coil positive +
Ground the test light to the chassis then turn ignition to the on position, take the test light and touch the coil to see if test light lights up. If so your getting power to the coil. You also can test off a spark plug wire place a spark plug in the plug wire have someone crank the engine and hold the wire approximately 1/4 of an inch from the header almost touching and watch for arc (SPARK) between the plug and the ground. If it's there then you know spark and coil and ignition is good.