I've been looking for upgrades for my 03' and can't find much. i've looked at CAI and exhaust or computer chips. It seems they only do these things for the impreza's. About the only thing i've seen is a kit to upgrade from single to doh cams. And they wanted like 3,200.00 for that. Where do ya'll go and how much?
I've noticed www.cobbtuning.com has an intake system i want but is $270 high for one? And is the cylinder head stage one worth it?

as far as engine things are concerned, impreza parts work. Any pulleys or flywheels or cams, heads etc will bolt on. intake should pretty much work too but youde have to check the fit in the engine bay. Headers, any earlier 2.5 liter header will work.