Strange Oil Leak

The motor was rebuilt less than 10,000 miles ago. When it was done, new pistons and rings were installed. The head gasket is not blown. I just had the heads off, and everything was fine. I will check to make sure the PCV / hose is clear.

Is it a must to have a breather and PCV valve both? I have just a PCV without a breather. It was my understanding this would work since the PCV would hold the crank under a vacuum.