The R terminal should have a 14 or maybe 16 gauge wire running from it to the + terminal of the coil. It supplies straight battery voltage to the coil during cranking. If you have converted to 12V properly, there should be a ceramic resistor in the wire from the ignotion switch to the coil or a piece of nickel/chrome wire from the switch to the coil + terminal. Voltage at the coil should be about 9.5 volts during normal running.
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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