Ok - I have an idea. I have an old G5 dual with one dead CPU. I haven't been using it much lately, and it's all but obsolete. Seems a shame to waste that gorgeous case.

Long ago, I hacked an NVIDIA GeForce 6800 GT into the thing, using some creative ROM flashing. With stock drivers, the video has never given me a moment's trouble.

How feasible would it be to perform the ultimate hack on this thing? What combination of mobo and OSx86 distro would get me the closest to a real quad-core MacPro using every possible scrap of hardware that's already in the case? My ultimate goal would be for this to be almost indistinguishable from stock. Can it be done, or would such a Frankenstein's Monster be an affront to god and man, escape to ravage the countryside, and ultimately result in my decapitation by an enraged crowd of teutonic peasants with torches and pitchforks?