the holes in the t-stat were more of a test than anything ,just wanted to see were my flow problem originated.Very tough to depress the spring so Ill be ordering another one for install .In the meantime I thought I had successfully completed a cetriC flush with the preston product,Really cleaned out the rusties nicely,Im guessing someone was doing straight water for sometime in the old girl.Im taking the radiator off to exam the tank ,this might be my problem since the heat of the radiator fluid isnt reaching the bottom hose,aka irriatable radiator syndrom.