The 2 vents off the valley cover are as close as you can get to the crank case without drilling a hole in the side of the block. All the venting on the rocker covers will be sealed. There's no where else for the crank case pressure to go but into the breather tank.
As Bobby was saying there is usually positive pressure in the crank case because of leak down from the combustion process. It needs to be vented freely out of the engine. Any build up in crank case pressure will affect ring seal and also try and pump your engine
oil out of the front and rear main seals
It's usually achieved in most motors using engine vaccume and a 3/8" hose connected to a rocker cover. Without vaccum giving it a helping hand you need some larger pipes to ensure no restriction hence the 2x 5/8" hoses. Both of those pipes are outlets. The system vents to atmosphere via the air filter on the top of the tank.
Cheers