Do you still have your air dam? If not, when you box it in you will have cooling issues since you have no low pressure zone behind the radiator for the air to escape. I'm not that far away from you if you want to come see what I've done on my car. Highest my water temp has ever been was 208 in June at Hallett during a 40 minute race when I was directly behind another car for a few laps. Turned the fan on and it dropped to 200. Normal temps are 190.
ETA: You don't need hood vents if you box in the radiator and you have an air dam.