If it's got a Delco regulator, copy down the part number stamped on it. I can cross-reference a part number to tell if the system was originally positive or negative ground, assuming it's got an original-equipment regulator on it. If it's not a Delco unit, my reference books probably won't be much help.
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!