Hi all this is my first post. I hope I got it in the right place!!

I have a red 1966 mustang 289 v8 coupe. It has an edlebrock intake manifold, edlebrock 650cfm carberator, Headers (I think they are a tri y header but i dont know), all magnaflow exhaust, C4 auto transmission, and a low rear end ratio. Ill get pics in a bit on my profile
To the car me and my dad have put all new hoses, vacuume lines, radiator hoses, heater hoses, gas lines, fuel pump, rejeted carb correctly, cleaned card throughly, put in a new high performance 180 degree thermostat, new thermostat housing, changed coolant, drained gas tank and cleaned it, changed oil lol (it had verry little in it when we bought it) and put slick 50 in the oil for better or worse my dad puts it in everything and so far its only done good. It quieted down the valves to almost non exsistant. It sounded almost like an aircompressor when we bought it.
ok so i dont know what you need to know for my question so i included I think most things about the car you'll need to know. My question is the here in the southwest how likly is the car to overheat? I have been driving it some and now its getting hotter the temp just keeps creeping up higher with the temperature outside. The highest its ever gotten id say is 210 while idleing in the drive way we were not paying attention to the temp.