Hello all fellow modders and enthusiasts. I got a Mac Pro case for free that was "damaged" (power button came loose, easy fix) and have decided to make it into an ATX pc case, since I think it's a cool looking case. I plan to transfer the parts I currently have into the Mac Pro case when done with the mod. Since I have a P6T Deluxe V2 and am running SLI, I will be converting the case to ATX, with all 7 slots available for use. It looks like almost all other Mac Pro mods I've seen have been conversions to MATX or are ATX, but don't allow multiple video cards. Hopefully the mod will be unique and turn out well.To start off modding, I stripped the case down to just the enclosure. This required removing the cabling, covers/panels, and the "divider shelf" between the top and bottom of the case. Once I got to this point, I decided to order an aluminum ATX motherboard tray to use, basically replacing the Mac Pro's rear panel. I decided to go with this tray, from mountain mods in the 2x80mm configuration.Once the tray arrived, I marked the rear panel of the case with my sharpie and went to work cutting it out with the dremel. Several reinforced cutoff wheels later, we have this result. (sorry about the quality of the pics, I only had my cell phone with me...)So far, so good.I then decided to mount the tray to the inside of the Mac case at the four corners of the tray. I drilled holes as needed in the tray and made up "standoffs" that I JB welded to the case.I attached the standoffs to the tray, roughed up the standoff and the inside of the case, and then put a "dab" of jb weld on the standoff and then set it in place overnight. I also drilled holes into the backplate and pro case to secure the back plate in place.There is just enough room, so I found, to still put a power supply above the motherboard plate (in the standard mac pro position), even with a full atx board. I decided to JB weld two "elevator bolts" to the inside top back of the case, which will support a crossbar that will hold the power supply "clamped" against the top of the case.While that hardened, I got a piece of 1" aluminum and made a crossbar to hold the power supply. During this time I also decided to install the new power supply jack into the back of the Mac Pro. I marked out the position I wanted......and then cut it out with my dremel. I then soldered a right angle power cable to the jack and installed it into the case.Once the JB was fully hardened... I put the power supply in place and tested the crossbar.I had to modify the motherboard tray to allow the latch on the Mac Pro case to function. I cut out a notch around the latch....and this is what it looks like installed.Next, I will cut the out a large portion of the divider plate between the top and bottom of case and re-install it. The mod could be done without a divider plate at all, but it's nice to have in, as it allows easier mounting of the hard drive and optical drive. I plan to cut enough away to allow my graphics cards to fit in the space created.I will post more pics and work later as the job progresses.