That one is supposed to power a vacuum-shifted gearbox somewhere in the speedometer cable housing or maybe on the back of the speedometer head to change the ratio so the speedo is accurate in both rear end ratios.
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!