Chris, look at it this way, Brian was running 2 open vents into hoses. All you need to do is keep the pressure from building up in the carankcase and valve covers to keep it from blowing oil out of the valve covers at high RPM's. This will not effect your vacuum since that all comes from the intake part of the engine. The PVC valve may hardly ever open except at high RPM since they are designed to only open when there is a build up of pressure in the crankcase, which is created by blow by in the rings.
Zip.