This cam core shortage isn't new. A year ago I tried to order a big block solid roller from either Crane or Comp Cams but I don't remember which. They didn't have a core and weren't sure when they would. Bullet, at the time said they had a core and could build it,but I opted to use the Cam Motion cam that I already had as the gain would be small vs the cost. It was pre-Covid.My machinist warned me about it as he was already experiencing the problem with cam core issues.As others have stated, this problem has been building for some time. Bill