I have an original coil in my 70 SS (402) and the last 2 times I took it out it seem to want not to fire very quickly, everything is completely stock, was wondering what the voltage from the coil to the distributor is suppose to be when your cranking the engine????? I think it is 11.6 to 12.6 to get the right amount of juice to the plugs, anyone that can help i'd appreciate it, thanks mike

The coil will get battery voltage during cranking, so it depends on what your battery is able to handle during cranking.

Should be minimum of 9.5 (10.4 preferred) when cranking. Any less means starter drag, points out of adjustment, battery problems or bad cable connections. Voltage when not cranking varies depending if points are open or closed, and those readings are of almost no importance.