We seem to get a little surge of excitement on this about every 6 months as new members come on board. The diff is a BW (can't rmember it its 21 or 23 spline)- no stronger than a t series (most likely weaker). It does not fit into a TA/RA2x - it is too wide. However I believe that it is the same width as a RA40 and my measure tells me it will most likely fit.
If you want to know a little more on how you could use the discs have a look at my tech article on this site.