filters are fluids are all you can do to take care of the truck. Injectors, turbos and head gaskets are all the expensive possibilities but it's largely just luck. Not chipping/modding the truck to the gills certainly helps your chances of not suffering a major repair but nothing can totally eliminate it.
I'm at 130K and have just had the normal (and sometimes expensive) front end parts, leaking tranny lines and a xfer case. I'm hoping to get another 50K miles without one of the "big 3" going out but who knows.