quaife = not recommended... go to
www.magnusmotorsports.com look under tech, Kaaz vs torsen a quaife is a torsen type of differential, which has some specific downfalls. however, depending on your application, you may prefer those over the clutch type. Kaaz are slightly louder, and they do "wear" however if you read the article, you can see how Marco, a very experienced car builder feels about torsen type differentials.