UVW or unloaded vehicle weights are meaningless. They are basically what the factory says it should weigh as it rolled off the assembly line. As for the trailer. Always look at its GVWR. While you may not hit that number, you sure as heck will never see a dry weight either. And by using GVWR figures you will have no surprises the first trip across the scales.
As for your basic question, the 7.3L should be able to tow a 10,000GVWR trailer easily. Of corse rear end ratios play into the equasion so you need to do your home work there too. Or be prepared to shell out for a different gear set if it is not a good one.
Next worry will be the hitch. Many trucks do not have a hitch rated for up to 10,000 pounds of towing capacity. So you will need to check that out too.
