look on the ID tag under the hood on the driver side strut tower,
what is the engine ID code?? ej251 or ej259 ??
The legacy has a 2.5 dohc but my outback is apparently a California emissions motor and the legacy is definitely not California emissions.
the emissions crap is all on the intake,
it has nothing to do with the block or heads.
the 03 engine should swap in , unless the 04 is an ej259.
use the intake manifold off of the original engine.
this guarantees that the car computer will find exactly what it is looking for.
is the outback or the legacy sedan a manual trans?