The WRX STi donor will have an upper  flat-four and a 5/6-speed transmission. The highest spec donor would be an STi Type-RA or Type-R, which will have a six-speed transmission and a driver controlled central differential and limited-slip front and rear differentials.
The WRX STi donor will have an upgraded flat-four engine and a 5/6-speed transmission. The top-spec donor is the STi Type-RA or Type-R, featuring a six-speed transmission and advanced differential systems for improved handling.