like said by another, 200 deg is not hot... and to throw my two bits in if anyone hasn't already said it... (and everyone has said great stuff)....

- coolant temps readings are only just that, coolant temp readings... not engine temp. One of the most common misconceptions is a thermostat rated for a smaller temp opening means your engine will run cooler... The coolant system is designed to transfer heat from the engine to the air, if you run a too cool thermostat, you're not letting the coolant absorb enough heat to transfer away from the engine. A hotter rated thermostat will absorb more of the engine heat, and though your coolant temp will be hotter, your engine will actually be cooler. So running a higher temp rated opening thermostat will keep your engine cooler, not hotter, and vice versa (that is, when all things else are running correctly).

- just because you have good visual flow in your radiator (cap off, engine just warmed up enough to open the thermostat), doesn't mean you're flowing coolant well. A rad can get clogged just enough that it'll look like it's fine, but, especially with a mechanical water pump, at lower engine rpm (and lower water pump rpm), coolant will flow fine, but at high engine and water pump rpm the coolant will start to back up, or rather, not keep up with the higher rpm... and will start to overheat and eventually puke. The engine isn't overheating, it's just the coolant overheating (though obviously once the coolant overheats and turns to vapor then the engine ends up overheating too, but only after the fact)

- always run a good mechanical water temp gauge in addition to your stock temp gauge, if you aren't already. You'll get a more accurate reading and you'll notice that even with the sensors side by side in the intake manifold (if that's where you're running them), they won't consistently agree with each other all the time... more data the better..

- what kind of fan are you using too? old school fixed fans are about as useful as no fan at all, clutched fans a lot better, shrouded over unshrouded any day, but you just can't even begin to compare to a good electric fan (but keep in mind that you'll need a higher amp alternator to run an electric fan)

- again, 200 degrees is not hot. Even if you had steam visually escaping from your rad's cap, that still doesn't mean you engine is overheating... Signs of your engine overheating are noticeable sluggishness, loss of power, and pinging. The only way to actually gauge if an engine is running too hot, is if you had EGT sensors at each exhaust port/header primary (or used a IFR gun, but that would only work with the hood open at a stop, unless you can convince a friend to hang onto the fender with the hood removed while you drove it around hard... hey, we all have a friend that would do that... ha)

But yeah, clogged anything is always bad, but you can have a good amount of sludge and old casting sand in the bottom of your block and it really won't affect much...