DDK - Die Deutschen Klassiker

Hi,
I am in the process of installing a 6 cylinder engine in my 914. I have a factory oil tank with a factory filler neck. There are 2 18mm vent connections on the setup, 1 on the filler neck which I believe connects to the crankcase vent on top of the engine, and a second on the top of the tank itself. I think this second would normally connect to the air intake housing but I am not using the original air box as my carburetors are fitted with k&N weather-shield filters which do not appear to have any breather connection. Does anyone have any suggestions where this vent needs to be connected? or have I got the setup wrong altogether?
Any help would be much appreciated.
Cheers Jonathan.

The one from the top of the tank usually goes to the crankcase. The other most people add an oil breather filter or even an oil catch can.

Thanks Stephen,

I have some hose I can use to connect up to the crankcase but I will have to look for some adapters for the connect to a catch tank or breather.

Thanks for the help.
Cheers Jonathan.