Certain years of stovebolt engines have steel camshafts and other cams are made of cast iron. One of the part number crunchers will be around shortly to explain which distributor gears are safe to run, and which ones will cause wear problems.
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!