I would say to stay away from cold air intakes for NA legacys. I've heard that they are unreliable, and I even heard a friend of mine say that they decrease power on NAs

. I think a smarter move would be to get a high air flow intake panel and keep the stock air box, like the 2.5i faq thread says. I have an AVO high air flow intake panel, and from the minute I test drove it after installing it, I noticed a nice power increase. It makes probably as much power as a short ram intake. Much better bang for your buck, in my opinion.