PVC or breather?

Brooks James said
I had a 327 SBC years that had a lot of blowby. I installed a pvc valve on both valve covers, problem solved. Remember when the SBC only had a road draft tube for crankcase ventilation??

Look at the diagram in post #3. The system needs an inlet. Doing it the way you did, there's no inlet, so there's no through flow in the crankcase.