The 92-98 Subaru 5-speed gearboxes excluding Loyale and, God forbid, Justy- will bolt up to the engine. The '99 and later trannys use an 8-bolt engine mount so they will not work. You will need to fabricate the tranny mount and add a different drive shaft, as the transmissions are a different length. Just any transmission will not do, you really want the '98 WRX tranny at is it fully capable of handling 300HP. The '93-'94 Legacy Turbo tranny is also a candidate, but is not as strong. The '98 Impreza 2.5 RS might also do the job. All of these are $3500 to $4500 new. You also need to fabricate a hydraulic clutch setup and shift linkage. You also need to change the rear gear to suit the transmission (none listed use 3.54).