RE: Engine knock/noise
As for oil look on the back to make sure it is rated for a diesel, CI-4+, CI-4 ( I think the new rateing is CJ-4 for the newer2077.5/2008 engines), as if not you will ruine your new engine real quick. An example is the Mibil 1 Truck and SUV can not be used as it is not rated for Heavy Duty diesel use it has a API rateing of I think CD,SJ/ SH for cars pickups and older car diesel engines.
For dino oil most use Dello and Rotella, for synthetic many use Amsoil, Redline and Royal Purple. Enjoy your new truck.