They aren’t easily interchangeable because the two mounting bolts are even further apart around the Blacktop trumpets. Be sure to see “Throttle bodies” For more info. These function fairly independently of another adjustment into the ITB and when opened, allow a small degree of air to bypass the throttle plate. https://blacktop4age58024.therainblog.com/31239053/new-step-by-step-map-for-4age-20v-itb