Analog is definitely the way to go. A dwell meter is actually a voltmeter with a different scale. With the points open, the dwell meter sees full battery voltage because no current is flowing. With the points closed the only voltage the meter sees is whatever voltage is needed to push the current through the points (very small unless the points are dirty or burned). The "dwell" is the average voltage between points open and points closed, and it changes as the point gap varies that time span. The best dwell is about 66%, points open 1/3 of the time. On a V8 that's 30 degrees of a possible 45. On a 6 cylinder, it's close to 40 degrees, as the total dwell available is 60 degrees between the cam lobes. Digital meters respond to voltage changes so quickly that the readout can become unintelligible gibberish.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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