That makes the cam scrap iron. I don't know of any way to repair a gear on the cam. A good replacement cam would be the Melling CCS-1. It's close to a clone of the 261/Corvette solid lifter cam, with a bit more exhaust duration for better cylinder scavenging without creating a rough idle. Those cams can be found new on Ebay, or ordered through a local parts store like O'Reilly, Advance Auto Parts, Auto Zone, etc. New or reconditioned lifters always need to be used on a new cam.
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!