Quote Originally Posted by NevaLift2Shift View Post
The rear backing plates are the only real difference on any of the year models from 02-07, wagon or sedan. Now, the STI's are a different ballgame. 02-05 have the same backings plates and 06-07 have a difference size, I scrapped my old ones, so I can't measure those.

I bought an '03 donor and I couldn't live without the 06-07 4/2 pot setup. The only thing I had to change were the rear backing plates (which I just measured and they were 113mm from center of each mounting bolt). The 4 pots from 06 and 03 front calipers will both mount onto the front, which measure 153mm from center of each bolts. The one major difference between the 02-05 and the 06-07 2/4 pot setup is the 07-07 calipers mount directly to the spindle or mounting plate. The 02-05 calipers mount to the caliper slide/mounting bracket.

If you are looking at upgrading brakes the cheapest route is the "H6" brake upgrade, which will have some slightly larger rotors off a legacy (anything over 16" wheels should fit). If you want a new 4/2 pot setup from RockAuto, I got new calipers, rotors, pads, stainless lines, and hardware for right at $1000.
Do you have a link to what you bought? I can't find any 4/2 setups on Rock Auto.