I may be wrong, but I believe most of the gross weight increase in the Viking has to do with the gas filled landing gear. I have heard (and again I may be wrong) that you can get a gross weight increase on an early Viking by installing the later gear legs. Maybe that would work with the 260, since there is not a lot of difference between the 260, and the early Viking, other than FWF. It might be worth a call to the factory to see if it has been done before. Just an idea. Grant.