Engine interchangeability in 2nd gen Legacys

[Shmak1982]

Hey, been searching locally for 2n'd gen (I think at least, 95-99 style) wagons. I rather have a 2.2 for fuel economy, as it will be used primarily for my delivery job, and ultimately for my mobile service business as a service unit. Anyhow, the long and the skinny of it is I have found a couple locally that are '97-'98 Limited wagon's with the 2.5. I like the body design (hood, body moldings, etc) on the Limited, and the leather with butt warmers is nice, butt truly do want the 2.5. Are the engines interchangeable in these cars if a guy wanted to pull the 2.5, and drop in a 2.2, or even a smaller (2.0?) from an Impreza maybe? I understand there would be great power loss, and I am also buying one just for my daily driver, and plan to keep the 2.5 in it, but my delivery car needs max economy, and power is irrelevant on this particular car. I'm sure it is like any other car I am used to, (I'm a long time Chevy guy, but have always liked Subarus and have decided it is time to snag a couple) and there is probably zero interchangeability, but here's hoping. Lol. Thank you in advance for your experienced knowledge.