Allthe tractors will carry the "20 Series" designation...even the 9000s. They're skipping the the TEN Series there. The 8420 and 8520 will be different than the 8120-8320 (which will be primarily unchanged). The 8420 and 8520 will have a larger frame (with front duals available) and have a front suspension. Plus these tractors will finally have a tilting hood. The 9420 will be the same hp as the 9400, but they will add a 9520 and step up the hp on it. By the way, the Frontier line will include much more than just Woods manufactured items. Those are just the first to be intro'd.