If you change the radiator do the thermostat too, and perhaps the hoses. I just changed out the original British-made Blackstone radiator in my 1990 240. It had plastic tanks but was still leak-free after 23 years. A bit plugged up inside though. I bought a Nissens aluminum radiator with plastic tanks, and it was a quick, easy job. The temp gauge now gets up to 9 o'clock quickly and stays there even on a hot day with the AC on in heavy traffic or on long hills.