I know this is a 2G question but there are never any responses for 2G questions so I thought I would ask here. I'm buying a 2003 WRX 5 speed. It has a 3" exhaust with a catless downpipe, a k&n short ram cold air intake as well as a stage 1 clutch and lightweight flywheel. The motor is knocking and I'm replacing it. My question is, if I port and polish the heads, intake manifold, and exhaust manifold, and also get 565cc injectors as well as a manual boost controller and push a little more PSI; would it be fine? How much boost should I go with? How beneficial would it be? Will I need a tune? Sorry if this is a stupid question, I'm new to turbo cars.