Oh yeah, I totally forgot it comes with a second drive cage. If the bottom drive cage is removed, there will be plenty of space, but I don't think it will fit with the drive cage installed.
that card should be about the same length as my 5870's ... a pair fit very snug and there's still room to put a 120mm fan for front intake. and yes you will need to remove lower drive cage as mentioned.
Thanks for the replies. I have a HD 5850 in there right now. I can't even remember if I have a bottom cage in since I haven't opened the side panel in a year.