all lego, GT, LSi, outback, bumpers 95 - 99 will swap. with limitations.
the outback and the GT grilles are taller, they hang down lower, so the bumpers are shaped different to accommodate. but the bumper / grille combination will swap onto any of the cars listed above.
fyi: rumor has it that the outback grille and the GT grille will swap with no other changes.