Measure the thickness of the spacer ring VS the thrust plate, and file, grind, or sand it to establish the proper end play- - - - -usually around .005". Just enough to keep the cam from walking fore and aft and changing ignition timing by altering the rotation of the distributor gear. I use a magnetic chuck on my lathe, and a tool post grinder.
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!