I would agree, the Disco II is bigger than a Disco I but probably not enough to affect you swapping roofracks though. I would say that if the length of your roofrack was a lot on your Disco II, it will look even bigger on your Disco 1 or may overhang by a few inches. I don't think the height from the gutters to the rooftop has changed between Disco 1 or 2 which is probably the most important thing.