Hi kanewolf,
K4200 requires a PCIe 2.0X16, the same like those on my mobo.
It has the same dimension as my quadro 4000 and requires less power.
The metal brcket with the ports at the rear side of K4200 is a bit different than the quadro 4000 one..But I suppose it should fit..
I have chated with Dell and Nvidia and the told me that it should fit, but I cannot find a formal compatibility brochure, so as to be sure.