I'm not sure on which head gaskets they use, but I was either going to go with Enginesus.com or SSI. After looking at some reviews of SSI, and I think they are out of the running (although they have a A+ with BBB). Enginesus.com sells/describes the gasket they use on their website, but no brand is given. Whatever it is, they are confident enough to offer a 3yr unlimited warranty.
I actually have two 2.2's at home, the one in the car and the original before the swap (don't ask me how the swapped one got fried, it's embarrassing). I was going to send the one that seemed to have valve issues back as the core, and keep the one that's in the car now (lower mileage too), as my local subi guy probed it when it was running and said it sounded like a crank bearing, all bottom end - oil starved. On that engine I might do the 2.5 short swap/frankenmotorize, and keep it around as a spare or swap it in if I have a long weekend.
So, that's the plan.
As the engine is coming as a long block only, I shouldn't have to worry about cam timing, since it's all going to come from the donor motor. Is there any reason I should request a particular year 2.5? Just the EJ251, right? Or would a 253 work as well/better/worse? Since i'm using the 2.2 intake, I don't need to worry about MAP vs MAF, right?
On a side note, does anyone have suggestions on the 4eat 'downshift under load' problem that is out there? I don't think it is in every model year the 4eat was used. If you're not familiar with it, during hard accelerations, up hills, when the car goes from 3->2, it drops in pretty hard. Feels like the power comes back in before the converter re-engages completely (however those torque converters do it) and gives you a kick in your pants. I had heard a rumor that Subaru had a modified tranny chip that would fix it, but I don't know the veracity of the rumor.