So I noticed that ARB makes an air locker for the R180A for the old Nissan Hard Body pickups, their part number RD182 (see http://arb.com.au/media/products/air-lockers/application_chart.pdf, they also make one for the 10 bolt R180. I confirmed with ARB that these units are available, 10 in stock.
The old 84-88 Nissan 200SX non-turbos were available with an R180 with a 4.11 ratio (according to http://www.geocities.com/inlinestroker/ratio.html), same as my 98 MT Forester. R180s are a fairly easy swap into a Subaru. So... ARB air locker in a Subaru?
So ARB, who were pretty helpful btw, said they did not know whether it would fit this particular diff, so they said if I measured one up and filled out this form they would tell me whether they had one to fit.
So does anyone have said diff they want to measure, or know enough about the R180s to say that this or one of the other R180 lockers will fit the 200SX R180 or one of the others that fits our cars? I know a few have talked about this before, but with doubts about the availability of the ARB unit. Well, their available now!
Not sure I personally will want to spend a grand on a locker for my car which cost the same amount, but I'm sure someone will!