The 12 volt flywheel ring gear has 168 teeth, not 163. There is also a different starter pinion gear, which has the same 9 teeth as the 6 volt starter, but the tooth spacing is different.
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!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!