Aren't the cases of all those dimension series the same size? I have a dimension 4550 and I was able to put in a BFG 6800 gt oc 256 agp8x, though the card is about 1 milimeter away from an IDE cable on the motherboard.
*edit* wait, is your case kind of slim silver? I could have misunderstood because I just looked at the dell site and have seen some of the desktop options and how big they are. Mine is from the older black and gray ones.
The easiest thing would be to try and find dell's forums and see if there are any posts about compatible video cards or better yet, you call dell and ask them (if you can actually get through and stay on the line with somebody, I have a couple of stories of crappy serviece from their tech support could barley understand the people there and they couldn't solve the problem so they'd like hang up on us...)
hope that helps any,
Edited by Wizdabest, 05 September 2005 - 06:51 PM.