Switching polarity is easy- - - - -just make sure the (-) side of the coil is connected to the distributor, and repolarize the generator after swapping the battery cables around by touching a jumper wire from the BAT terminal of the regulator to the ARM terminal for about half a second. You'll get a pretty good flash- - - -that's normal.
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!