Neither, actually. I re-used the M54 hose #11617504535 ($7 at ECS for Uro, $13 for Rein, $46 for OEM):
Photo of that item's location in the original CCV system, taken from GrahamE39 on Bimmerforum. Note in the below picture it is "connecting line #11611440317" (different part number because the pictured car was an M52TU).
Because of the pre-shaped bend in the hose, and the orientation of the Y-shaped NORMA fitting, I needed to flip the hose as shown in the below pictures. The M56 outlet and intake manifold's inlet use the same size NORMA fitting, so reversing isn't an issue.
In the first photo you can see it is routed above the fuel injector electrical connection thingy (that's a technical term), and that the second port of the Y-fitting is closed off with a vacuum cap. In the second photo you can see that the only real downside to reusing this hose is that it creates a slight lift on the intake manifold's beauty cover. I'm really not worried about that, though, because you only see that lift when looking from the side. From straight-on it looks tidy.
