When I built my motor I had a cam journal not oil properly and locked up the cam in the block so I pulled it all apart and took it back to the machine shop they said they could bore out and put cam bearings in the whole block but that if I did so there might be the possibility that some day I could spin a cam bearing cutting off oil supply to that journal.
Now I know the first journal next to the cam gear has a bearing from the factory but the rest ride metal to metal. Consider the fact that these motors will last 500k miles. I decided to get another block rather than take the chance that I might have 6 other points of failure in my motor.