Overheating
Vent,
Like Vette-Dude suggested, I would do a search of earlier threads on "overheating" There are at least two or three (one is mine) on the subject and the causes include bad thermostat, bad water pump and clogged radiator (both inside the radiator and outside).
I will leave the specific recommendations to the generous people here on the CAC that know a world more than me, but I do have a question. When you say your are overheating are you really overheating (i.e. the engine light comes on and you have to pull over) or are you just running hot. Like Edmond said 230 is too hot if you are traveling at highway speeds, but I do get to 230 sometimes when I'm sitting in stop and go traffic.
This is what I've picked up from reading the other posts. Take if for what its worth and hopefully someone else that actually knows what they are talking about will help out.
If you are just running hot, then you should check the exterior of your radiator. Someone posted some pics and you would be amazed at the stuff that gets sucked up in there...leaves, sticks, plastic bags.
If you are overheating (i.e. gotta pull over cause you're over 260) then you may need to check your thermostat or your water pump.