1998 Subaru Impreza 2.2L MT 4WD L Wagon Differential assembly-rear. Individual, driveline - 27011AB151 | Subaru Part Wholesale, Libertyville Illinois
It's the same as the rear diff in five models, 171 variants from 1995 to 2019. Click on "what this fits" and "show more" for the full list.
Could also try the same thing on car-part.com.