Hi All,
Trying to get around to this. I didn't feel my case was a good example of this swap and will mention below why.
I bought a 2017 rolled STI from salvage around 5k USD but with transport it cost around 7k total. There is virtually nothing I used except the engine, engine harness, all sensors, tranny, and rear diff, wheels. front brakes,
Then I moved everything I could over along with JDM V8 drive shaft, axles, knuckles, hubs, (new) rotors 5x 114.5, brakes, Linkage (I got a new short shift one instead of dirty salvage), cross member
I would assume you need to get V8 of the following but I bought new rear endlinks, Ball socket and rear endlink kit, front center adjustment kit and new swaybars and bushings. see above for the rest of the suspension.
I am less of a help with the engine and turbo. I already had a custom GT30 setup so I had little problem going to the rotated STI setups - I just bought the perrin down and uppipe and they fit my setup perfectly. I used stock engine at first with stock headers. I already had a FMIC and just added fuel rails and new injectors.
ALL wiring merge was done with iwire to a Haltech Elite with TGV deleted and no emissions (I don't need to where I live so also not a great example for swap).
DBW was done easily with iwires DBW adapter**
I used spider DCCD and iwire did all my harnesses
I used the RS Radiator because the 2017 doesn't fit but I may upgrade to aftermarket. Needed to cut up hoses for V8 aftermarket silicone hoses to get it to work.
- review - I don't know if I would recommend this, since it is really a gamble with salvage cars, but when I looked at the V8, V9 engines and trannys they were old, rusty and beat up and the wreckers never really gave good enough background on the pallets that I liked. so I went looking for salvage I just tried to make sure there were no cracks on engine and tranny and since mine didn't start I just went through the gears and checked the oil, the ones that start and have engine running all were going for over 12k for anything newer than 3 years with major damage. Those with hail damage were going for 25k or more so I think I got "lucky" even though I got a burnt engine and replaced with long block. I knew I wanted a short block anyway so i did it for the tranny and the brakes and engine peripherals and heads (the small bits add up if you buy them new from dealer or aftermarket).
A friend and I did all the labor in a garage so its doable for anyone with willpower and some researching. we did it in around 45 days with me every day and my friend helping on nights and weekends.
Would I do it again, absolutely, learned a ton and now can do anything on subarus I feel. Cost effective? so will say no some will say yes, because I have all new powertrain and an awesome ECU and a car I love (again). My case isn't a good example, but this was my experience.