I was digging around inside my buddies Dimension 8200 a few months ago when the CD drive failed and the computer failed to boot properly (it thought everything plugged into the IDE plugs was a CD-rom, even if nothing was attached). I didn't really notice anything really unusual about the components aside from the way it opened (it opens like a book rather than haivng a side remove) and the PCI cards are held by a piece of garbage plastic snap as opposed to screws (damn firewire card kept trying to move when you shut it). I'd give it a try and if the MB won't fit, go buy yourself a new one, they're not that expensive and propbably superior to the OE Dell stuff, even at the same hardware level.