It also is an older plane using even older engines first sold in 1972
Not excatly right, for the 900Ex engines are 731-60 (Ex came up in 1995,new blades, more efficient but a little somehow fragile..) 5000 lbs of thrust compared to the TFE 731-5BR (4750lbs).
Yet you have to see, what range you would expect once you have done your 1000nm leg without having to refuel...