LT1 Thermostat Replacement

Yes, the upper radiator hose connects to the housing. You should flush the cooling system also if it hasn't been done regularly, according to the owners manual.

Sorry about that. I looked at the picture and thought it was the top. I should have read the procedure.

Your 'vette should not be running at 230 degrees. First, replace your radiator cap or have it pressure tested. A cap that doesn't hold pressure could cause it to overheat. Some questions. Did you use Dex-cool anti-freeze and mix it 50-50 with distilled (or filtered) water? Did you jack up the front end when filling the cooling system to get the air out? You might have air in the system if you didn't. Did you flush the engine block with the car idling, temperature control on high, flushing water through the heater hose that attaches to the block? Or did you only flush the radiator? Do you have an analog gauge on the dash that might not be accurate? You may want to take the radiator out and clean the fins with a high pressure garden hose, also check for debris betwen the radiator and AC condensor. While it's out flush it again paying attention to how the water flushes through. You might have scales inside the radiator restricting flow. You could try doing a chemical flush yourself or take the radiator to a radiator repair shop and have them flush it. They can do a more thorough job of flushing and while the radiator is out, clean your AC condensor with a garden hose.