Both gc8 WRX/STI and GD WRX drive shafts are the same. female end. The gearbox has male stubs on it for the shafts.

GD STI shafts are thicker with larger CVs. 02 STI have the same setup as WRX with a male stub on the gearbox. 03+ STI however, have male stubs on the shaft itself IIRC.

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RS Liberty - Because WRX's are only good for parts...