Help me identify this part

A buddy of mine (Chevy guy) is rebuilding a 360 Mopar engine for his dually truck. He found this washer in his parts tank but not sure it was from a 360 or not. Honestly I’ve never seen one in a 360 but the only place I told him it could go is on a camshaft between the thrust plate and timing gear. Did you guys ever see one?9980103F-CD18-4674-8B8F-546BF80C62F3.jpeg