what year is the car?
short-yes its possible we have a shop close to me that does WRX swaps all day. they did an 07 STi swap into a unicorn (older subbie). they are primarily subaru related.
long- It can be done, but give me the year of the car and such so I can do a bit of digging for you..also whats your location? if ur close to here i will give u the shop number and u can talk to them. the shop is very good...ive seen a timelapse video of their work..they did a whole WRX swap in 6 hours...THATS skill
04 Mazdaspeed Miata #2373/4000: IHI, BBS, Harddog, Flyin'Miata.