Chevrolet Repair: 89 camaro running hot, nox sensor, ac delco

Question
I have a 89 camaro, it has over 200,000 miles on the original motor. It started running over the normal 220 degrees. I figured since it had so many miles I would have the motor rebuilt. I had the motor rebuilt, the shop I used put a 350 hydraulic engine instead of the 305. They rebuilt the heads on the 305 and use them. When I got the car back it seemed to have the same problem, the shop told me that the temp gauge was about 20 degrees off. Around a month later I had the water line that comes off the back of the manifold break on the way to work, steam started coming out from under the hood. I had the car towed home, and I repaired the broke line, it was a plastic hose coupling they used to splice two hosed together. After that I could smell antifreeze in the exhaust. Took it back to  the shop and they found that it had a hair line crack in the head, he said it was hard to see because of the carbon build up, that has me a little confused because that motor only had a couple thousand miles on it and I've been using 91 octane gas. Got the car back with no change got tired of call shop so I started trouble shooting the problem on my own. Everything that can be changed on the motor that is related to the cooling system is new. Radiator,heavy duty water pump, tried several types of thermostats it was a staunt 185 degree in right now,new nox sensor,egr valve,pro comp distributor, iridium ac delco plugs, I installed a new fan motor and a switch that starts the fan at around 190 degrees. I also replace the air dam that mounts under the front bumper, new pro comp water temp gauge. I've ran out of parts to change, I would of taken it to a local shop but I just don't trust any in the town I live in. Even on the highway temp stays at around 200 degrees, and now that it cooler in or area I can get away with driving it a little more. When I get in town the temp will start climbing and the fan is running. Any suggestions would be a big help, I would sell it but I have to much money tied up in this car. If I can get this car to running cooler I can charge the new A/C system that it has on it. Again any suggestion would be appreciated.

Answer
just some info.  This car is meant to run at or above 210.  I just thought some more.  Maybe dumb shhop put intake gaskets on backword and the flow from the front ports is stopped.  Had that happen once at the dealer car would overheat after a while but it would not cook.  And i know you don't want to hear it but sometimes you need to stop the losses and part with a demon possesed car even if you take a big hit.  Unfortunately this car doesn't have very much value even running great.