What kind of oil are you using? Most oil does not contain enough Zinc these days to perform properly in a non-roller application, especially during cam break-in.

When you install the new cam, be sure to use a "racing oil" that contains a sufficient amount of Zinc. The lack of Zinc has become the number one cause of camshaft lobe problems with non-roller cam engines. I would use it not only for break-in, but for the life of the engine.