The subaru gearbox gives out power the wrong way around so you could drop in a Subarugears box from Hurstville which has reversed diff and pinion. I did this two years ago with a five speed box from a turbo Impreza and the results are outstanding. Dropped revs from over 4000 at 110kph to 2200 at the same speed. Used a subaru slave which was not recommended - the SVX has no room for the standard slave - and have found clutch feel to be great. No adapter plate.Uses t3 auto short axles on both sides. A guy from California has developed all the bits and pieces for the shifter but costs over a thousand dollars. Am saving for this. Budget about 5K for the box all up.