Hi I'm sorta new here lol but ye basicly I have a 51 plate 1.6 focus its had a miltek exhaust system fitted inc manifold and a k&n panel filter fitted I've had every engine focus bare the st and the rs but this is quick I've had 140 (private road off corse ) but now the millage has hit 130 thou so the bottom end has started to knock so was thinking about changing the engine to a 2.0l but apart from the obvious engine ecu key exhaust and engine wireing loom what else would I have to change ? Thanks in advance jake