I've heard that the Sti 2-Pot rears have a larger diameter parking brake drum, so you have to get the WHOLE parking brake mechanism with the rear rotors. Don't know if that's definitely true, but I've heard it a couple times.
What I did was get the vented rear rotors (stock are solid) that come from the WRX (or maybe the Legacy? Whatever it is, they work. I got them from SPD
), and the wider calipers. This setup with the vented rotors greatly reduces heat buildup, and lets you keep the parking brake. Along with the 4-Pot fronts, my car brakes SO much better.
[This message has been edited by mav1c (edited June 06, 2001).]