Not a bad choice, but then again the BD7 is very good car, perhaps more accomplished in some ways.

What else is there? The yokomo fits (but no point in using because of the internal ratio), and I would be pretty sure with minimal effort pretty much anything else would fit. Like above, the question is if there is any point. Xray is one of the most refined diffs (and brings the internal ratio higher a tad), the Schumi is even more refined and improves the ratio even further. Otherways, there is little incentive to fiddle around (apart from the aesthetics, but I leave that to each and everyone).