I just picked up my 97 Outback that got a new engine due to a timing belt snap today. I got a Phase II block with the Original DOHC heads that were ported/polished, 3-angle valve job, shims on the lifters for more valve lift, head milled, ACT lightened flywheel and street clutch installed. I still have the stock airbox and exhaust on it. I noticed that it it silky smooth all the way up to redline with smooth power delivery. It idles silently, it's awesome. I plan to get a new intake, exhaust, and some piggy back ecu to take advantage of the new found flow.