Here is a list of STI parts that can be fit to varies year Imprezas and WRXs since these questions come up all the time

Brakes:

Sti Front Calipers (all years): Fit 97-07 Impreza/WRX, requires STI brake lines, rotors, and at least 17" wheels
STI Rotors ('04): Fits '97-04 Impreza/WRX, 5x100 bolt pattern, only with STI rear hub
STI Rotors ('05-07): Fits 06-07 WRX/Impreza, 5x114.3 bolt pattern, only with STI rear hub
*note* Rear STI brakes require STI hubs/rotors or conversion rotors to work on WRX

Suspension:
STI Rear Lateral Links: All GD WRX/Impreza sedans
STI Front Control Arm: All GD WRX/Imprezas
STI Rear Trailing Arm: All GD WRX/Imprezas
STI Sway Bars: Rear fits all WRX/Impreza, Front fits all GD, may have header clearance issues on some GC/GM
STI Springs: All GD Imprezas
STI Struts: '04 STI struts fit all 5x100 bolt pattern Imprezas, 05+ fit only 5x114.3 bolt pattern hubs

Side Notes:
-'04 STI springs/struts are not interchangeable with '05-07
-Minor changes in aftermarket springs from the '05 model to the '06 model STI
-For STI brakes, makes your you wheels clear the calipers both in diameter and offset.


If those in the know could help me fill in the blanks and stiplulations, I would appreciate it

 

A few quick notes. Make sure your wheels clear the STi calipers. As for the STi rotors from '05-'07, the bolt pattern on the rotors are 5x114, unless there are 5x100 holes on there as well.

Rear lateral links: Not sure. I do know that GC and wagons use the same rear lateral links, while the sedans use something different. (Different RSB mounting point.)

Front Control arms from the STi should fit on the GD's. I think a friend's control arm went out on him and people said that he might as well get the STi aluminum ones. Just as cheap or something.

Sway bars. Can go on any Subaru. Not sure about '08, though. It might require you to move the endlinks from inside to outside, vice versa, or a combination of both. FSB is a different story. For earlier GC and GM models, they may not clear the headers.

 

but would sti springs fit into my 2.5i struts? sorry but im curious

 

yeh, the sti rotors won't fit because of the bolt pattern, at least I think...

 

All noted. Lets get some more good info up there

 

Don't forget to list whether or not wheels will clear. Chances are the stock WRX wheels will not clear the STi calipers.

 

rear brake calipers fit but the rotors will not. you'll need to get STI rear hubs as well, or the super expensive conversion rotors that are designed to fit the stock hub/e-brake assembly and the brembo caliper.

 

Noted. Need some more help on the suspension section

 

Springs are all interchangeable 02 through 07; any impreza (forester too, i think)

STI 04 struts are interchangeable; 05+ STI struts have a different bolt setup to match the new 05+ 5x114.3 hubs

 

OK, so that is to say any GD impreza can swap springs even though the aftermarket applications are different depending on year? ie, 04 is different than 05. Just want to clarify this

Also, 04 sti struts fit all 5x100 GD imprezas?

 

Many after market companies sell the same springs for all years...

I figure they are slightly different but not by much. I don't know exactly.

Yes, 04 STI struts fit all 5x100 GD imprezas.

 

I'll post a ton of stuff here tomorrow morning.....

 

So I guess he never woke up?!