the Ballast resistor should only be powered during cranking, it seems to me that you have wired the resistor into the "run" circuit. Remove the resistor from this circuit and identify using a test light/meter the "start circuit". the resistor is only used to assist starting when cranking during battery voltage drop. Check that you are using the correct coil, it should be marked for use with/without resistor. I have a 69 and have never experienced starting problems. I beleive the vehicle did not come witha a resistor circuit!!!