Well after 100K miles on my '02 and lately running consistently around 210 degrees without the air on and 220+ with it on depending on the grade of hill I'm on, keep in mind these temps are not towing, I decided enough was enough. Thanks to this site I knew what the problem was so I relocated the overflow away from the radiator and got me a new radiator on Ebay for $219 and a Cummins 180 t-stat and man I gotta tell y'all, it was 96 degrees outside today when I picked her up, perfect day to try to heat her up! I did my best with the air on full blast and lugging her and finding the steepest mountains I could, not hard being in WV. Anyway, I'm glad to report that I could not get her to break 170-175 and that was as hot as she'd get, when coming down the mountaing it would drop down to 150ish, great stuff! You would not believe the crud on the radiator, think of pudding skin, it was like 1/4 inch thick and covering about 80% of the engine side, unbelievable.

 

Yeah, a little maintenence really helps the ol Cummins don't it. I cleaned my rad and replaced the fluid and really noticed a temp drop too. Did you mean to say you relocated the puke bottle that catches the crankcase oil vent gas? I'm not sure relocating the overflow would affect temps. Kurt