May be the SD-10A range as 70KM is under the ideal set of conditions, a specific altitude and at specific aircraft speed. May be the range increases if its launched from a higher altitude or more speed. Thus range is still debatable, plus who knows they for the time being want to keep the 70Km version for export and keep the higher range version for themselves. Plus, the SD-10A specifications as told in the 2008 Zhuhai Air show showed Operational Range as 70KM.
http://cnair.top81.cn/missiles/SD-10A.jpg
As for the C-802AK thingy, the original C-802 version had something close to 120Km range, then came C-802A version with 180KM and the K designation means that its air launcher version of the missile and not land launched version. So, C-802AK means that its the 180Km range missile which is air launched. C-802KD would means its an air launched version and
D designates that its for Land Attack purposes, thus with different seeker tech and may be guidance system also differs. So K means its air launched version and D designates Land Attack version and A is the updated version with 180KM.
