Originally Posted by
racer_x
That will not fit.
02-05 WRX (2.0) are interchangeable, 04+ STi (2.5) are different.
Actually a WRX clutch will fit an STi 6MT. People have been using WRX clutches for awhile to do 6 speed swaps on the cheap. IIRC the WRX clutch is smaller in diameter than the STi so it fits in the 6MT, but an STi clutch is too big for the 5MT.
I still wouldn't put a WRX clutch in an STi if I could avoid it though. No point in skimping on something like that even if its a good deal.