Before you drain your old coolant, be sure to throw in coolant flush which can be bought at any auto parts store. Follow the directions on the back. It'll kill any calcium build up. And if you really want to get crazy clean, take your radiator out and take it to radiator shop to have it "cooked ". That will clean every little bit of dirt and calc out of it. But since you have a new one going in, don't worry about cooking it. Once all clean and new coolant in, you could also use Royal Purples "Purple Ice" or Redlines "Water Wetter" which drops temps down a little more easier. Just my opinion though.