[65BLUBIRD]

Because of leaks, I recently had my radiator recored and the supply tank replaced. The recore is a higher efficiency cooling than the original. The gauge in the car was working fine before the work. The gauge does go up a little but not to the middle where it was before. When I turn the engine off with the key on The gauge does creep up higher. Am I right in thinking the new thermostat is a defect and I am not having a problem with the gauge or sending unit? I am located in so cal so I am not too worried about getting this fixed right away. If I block the radiator with cardboard, how long should I run from a cold engine to determine if thermostat is problem?