The plumbing to the return port is only for a flow issue on the se series dk's. No other series tractor requires or benefits from this "quick" fix regardless of backhoe size. As far as there being a KB 2485 back hoe on a ck series tractor, yes, kioti does not specify that hoe as a fit on it... however, it is only 40lbs heavier, preforms slightly better than the KB 2475, and if you look at the specs, is the same as the comparable woods 8.5' backhoe that many dealers have installed for several years on the Ck series tractors.