I tore apart my "donor" turbo to see exactly what it is that fails... it was pretty obvious.   
On these first couple pictures, I inverted the colors to make the problem extremely visible... plus they were dark    
http://i7.photobucket.com/albums/y292/mrmeanr/DSC00001.jpg 
http://i7.photobucket.com/albums/y292/mrmeanr/DSC00002.jpg   
Now this gasket is not only entirely too thin, but its also about an easy inch too large, as well as split.  With a 76mm wheel spinning at 80,000rpm... you can see why that could become a problem pretty quickly.   
Another thing i noticed was on the backplate... its surface is rough and unmachined, as you can see in this next pic...    
http://i7.photobucket.com/albums/y292/mrmeanr/DSC000031.jpg   
in other words... garbage.   
Now the good news is, i never planed on running this side of the turbo... oh no, its too little.  I had some wheels lieing around so i took a pic of the difference in size.   
http://i7.photobucket.com/albums/y292/mrmeanr/DSC000041.jpg   
Even the large wheel is small, compared to what i have my eye on  :burn: