I think the bigger question is did you come from a diesel background before this truck? I too had similar concerns when I first got mine, but as I got more and more familiar with this particular engine, and a few 6BT's and IDI's before that, I realized these are very different animals compared to the big block domestics, and BMW engines I came from before them. These engines are very backwards mindsets. Gas engines, you want to get the heat out, diesels, you want to keep quite a bit of heat IN. Gas engines we want higher compression and higher octane fuels, where diesels we want higher Centane numbers for easier combustion... stuff like that.
I normally run somewhere between 200-218 oil temps in south Texas - which sorta made me nervous too at first, but I have a sparkling clean oil-pickup screen, and the oil that comes out is what you typically expect to come out of a diesel engine. The simplest solution to lower the temps a little would be the AFE +2 quart aluminum oil pan. I'm going this route in the very near future. Extra oil = more oil to have to heat up, plus the cooling fins may help a bit. I went this route on the trans pan, and noticed about a 10-18 degree lowering of average temps depending on season.
