Have you tried immediately hooking up the coil wire after a week to see if it makes any difference. Could be an intermittent issue in your ignition switch where voltage is not being applied during cranking or it is very week. I would also check the voltage at the coil during the crank cycle and run to confirm. If I recall, 69 is the oddity wrt applying coil voltage during crank. In 67/68, voltage during crank also comes up from the starter solenoid.