Analysis of Spatial and Physical Dimension (AKA Eyeballing the fit)
The initial consideration was whether or not the Xbox 360 motherboard would fit into the Atari case. At first glance, it was obvious it was going to be close when it came to the length and width of the motherboard, but definitely workable. The problem, as it turned out, was that I had to deal with a two inch high heat sink and an equally as obtrusive attached circuit board that contained the RF antenna and power switch (RF board). It quickly became obvious that although the 360 would fit, it would require some adjustments of the Atari case.
After some thought, I decided that the easiest solution would be to place the Xbox motherboard into the Atari case backward. The reasoning is that I could more easily integrate the RF board and USB hub into the thicker backside of the Atari case. At this point I was ready to cut!