[B_man_Al]

As I mentioned in post 5 there will always be an error in the measured voltages when making them on a running engine . This applies to measurements made with an ANALOG meter where the meter movement "averages " the voltages and current being measured. This is exactly what happens when you make a dwell angle measurement.

When a digital meter is used all bets are off. They respond to all the glitches and spikes, particularly across the points where there is a significant voltage spike due to inductive kick form the coil as they open.

If you make the measurements with the engine off (and the points closed) you can use either type of meter and get accurate results. To correct for the differences in battery voltage between running and non running just multiply all your non running measurements by 1.2 ( 7.4/6) and you will be pretty close.
Al