Do you think it's running too hot? You didn't mention a specific overheating problem, and you aren't likely to get 100+ degree days in Puyallup, so it's probably OK as is.
The engine will run more efficiently at warmer temperatures. As long as it doesn't boil over or approach 212 on long hauls or steep climbs, it's probably OK.
I picked the 180degree for my 250, but that's with a 3-row core. It does get over 100 regularly here in the summer...
-Boyo
