The 3.6l come in b6 passats as well, not just CC. But I think you're going to have a VERY difficult time getting a transverse engine (VR6) to mount in a longitudinal engined car (B5 passats). Not saying it's impossible but I would think it's 100% not worth it. Just buy a b6 passat with a 3.6L and make an R36 (which was available in europe). Or buy a W8, then you'll have your AWD and similar power to a 3.6L VR6, and it'll be stock and you won't have to worry about all the issues you'll have with doing such a drastic engine swap. Not to mention, doing a 4 motion from an R32 into a Passat would pretty much be impossible, you'd spend so much time and money custom making stuff to fit when you could just buy a 4 motion passat and have, what I consider, a superior awd system. Basically if you think about it at all, it's in no way worth doing. I'm assuming you just like the idea, but have no clue to the work involved.