Its not going to work. My backhoe at ~650 lbs (and the CG far to the rear) is all this YM240 wants to lift. The front loader is plenty of ballast, but it feels like it could only get another 150 lbs off the ground. Driving on bumpy ground with the backhoe squeals the pressure relief valve. This seems like a signal that its at its limit.
Aside from lift capacity, we've read of Kubota owners ripping the back out of the transmission housing from excessive weight, and seen a few examples of tractors split in half at the bell housing. In summary a 1000 lb implement is beyond the intended use of these models.