What about for a standard 6v ignition system?
If a regular dwell meter doesn't want to work on 6 volts, it's pretty simple to check dwell with an analog voltmeter. With the engine running, check the voltage at the coil + terminal, grab the calculator and figure 33% of that figure.
For example: Voltage at the coil + terminal = 7.3 V
7.3 X 0.33 = 2.40 V Adjust the point gap until the voltmeter reads 2.40 V. at the distributor side of the coil (engine running). The dwell will be 40 degrees.
Jerry