Still overheating

Evans coolant. Ill check into that. I really hate to cut holes into the shroud. It seems to be doing the same thing it was before the radiator change. I had a radiator out of a international truck, big and ugly. I hate to wrap the headers, But I think that's where the problem lies. I bought fender well headers, but can't bring myself to install them (ugly). I read once to remove the thermostat, and put a washer in it's place. I have no heater. No need with these headers. A 13 mile trip brought the temp to 220 at 55mph yesterday. I have some Wynns water treatment I'm going to put in.