straight up on the needle is about the common operating temp for the stock t-stat in the 5.9's. a 180* is what we all go to. it can be done w/o removing other components. but it is easier with the AC compressor out of the way.
i would also look into a billet belly pan if you plan to stay with the factory intake manifold.
2006 Hemi Ram QC 4x4
2000 AF RC Dak R/T
2000 BW CC Dak R/T