First off, where in Kansas are you??
I had issues with my /6 last year. It ended up being the thermostat. (because I didn't have one) Test it on your stove before putting in the car - this has been my year of buying brand new thermostats that didn't work! It's funny - for those failsafe ones to work, first they must open LOL
If you want to test the radiator, there is a radiator shop in Park City (near Wichita) that can test it and repair it for a very reasonable price. Also, make sure your system is pressurizing. if not, then it will boil all your coolant out and cause air traps.
