PCV system

OK who is the PCV God?? It would seem that a standard vent cap would meet the rewuirment of releasing the crankcase build up and prevent back pressure and blow out but if nit them what does that little PCV do with the Vac and how does it prevent it from backing up is just with the Vac it sucks out the pressure? I am not worried about emissions at all but I dont want any blow by so what is my best bet. i have the Mopar Alum Valve covers so to do anything other than a vent cap i will have to drill so talk to me.