It is going to depend on the axle and what tools you have to work with. For example, Dana axles typically have shims behind the bearings which require you to press the bearings off the carrier to get to them. The bearings can easily be damaged and rendered unusable unless you have the right tools to pull them off with.
If you have the tools to pull the bearings and the truck will see minimal highway mileage I don't see a problem with reusing bearings and going with the basic install kit.
