99% of the subarus in Qatar have the R160 rear diff which is good up to 300hp in rwd terms.... I drove my R160 for almost 2 years in rwd setup (I was makeing around 140hp at that time, and yes I abuse it,,,, clutch kicks, burn outs, drifting,,,ect) but after that I wanted an lsd setup (mine was open diff) so I bought a used R180 diff from a JDM STi and installed it into my car..... 3 years now no problem (thu I don't drive my car much since 2009) but as far as I know the R180 can hold up to 400hp in rwd setup...

oh and I still have my front axles on :P