What type of Kubota do you have? Is it a Grand L series? Is it a L3130, L3430, L3830? If you have one of these machines with the Kubota LA723 loader, it is rated as: Maximum Lift Height 102.4 inches
Lift Capacity (500mm forward) 1400lbs.----which is at the tip of the bucket.
Lift Capacity(Pivot Pin) 1870 Lbs. which is at the pins where the bucket attaches to the loader frame.
Lift capacity(Bucket Center) 1587 Lbs. All three lift capacity's are rated at the Maximum Height for the loader.
Lift capacity(Bucket Pivot Pin, 1500mm height) is 2317 lbs..
Lift Capacity(500mm forward, 1500mm height is 1852 lbs..
If you have the LA513 loader, the capacity is less. If you have a L4330, L4630 or L5030 and the LA853, you are going to be able to lift about 400 Lbs plus in all operating ranges.
Remember, when you use forks, they usually weigh somewhat less than your bucket, so you will gain some weight handling capacity when using them. But....the further the load sits out on the forks, the less lift capacity you will have.
I have a L3130 with the LA723 loader with QA and it will handle some fairly impressive loads for a machine this size. I have moved 2000 Lb. rocks with it, but you have to be VERY careful when doing this as the rear end gets very light even with loaded tires and a 575lb. box scrape on the 3 point hitch. Plus, you don't want to lift them any higher than you have to when moving something this heavy, with a machine this size. The machine weighs in at approx. 6000lbs. with loader & bucket (with tooth bar), loaded tires and 72" box scrape.
Always use your ROPS and seatbelt when using the loader.
My opinion, if I were going to be moving pallets weighing over 1200 to 1500 Lbs. would be to get a large skid steer loader. Or a tracked skid steer which will handle VERY heavy loads for a machine their size. Of course, the are VERY expensive, so a wheeled skid steer might fit in better if it were me.