Old racer suggested this -
Put the cam in most of the way, then put machinists / prussian bluing around all the journals on the cam. Then shove it in the rest of the way without turning it.
Now, pull it back out a couple inches, again without turning it.
Where the bluing is wiped off, those are the high spots.
USUALLY a little scraping with a razor blade (the goal is to scrape the bearing, not your fingers, but both is still ok) and the high spots go away, then the cam will turn and even spin.
Idea is to just take off whats needed without adding too much oil clearance all around. Tedious job but rewarding when it works.
