This is the fitting we use to adapt our NC engines over to a catch can setup. It's still a tight fit and might require modification of your intake manifold, but this is as low profile as it gets! We used 2 lines so it requires 2 of these fittings. If you're only using one, just use a block off plug. 

Notice: Using this with the Radium plate, it's still not easy. This will make contact with your intake manifold and modification might be necessary.