stock STI has a 20 front and 20 rear...
i believe the wrx has a 17 mm stock rear? and i'm not sure how big the stock front is.. i know my 93 GC (FWD) had a stock 17 mm front, and the rs 2.5 had a 18 front and 13 rear... or i should say I **think**
so i would fathom a stock wrx is something like 18 front 17 rear, or 20 front 17 rear...
Still i definitely want to give it a try. thanks