Tight fit it is! I just measured the 5850 and looks like 10" may be just a touch too long for this setup :( The 90 degree barb barely touches the 5850 shroud, so I may end up using my 5770 until I can find a suitable replacement. Let's cross my fingers for whenever I finalize on the motherboard!
I was planning on just filing the edges down, but how can I turn down trim! I might need to snip off a little bit more depending on how thick it is... I hope there is enough wiggle room.