this may sound stupid but i work on all kinds of cars. i bought a 1958 international 340 utility tractor gas engine done a little to it been using it. one it overheated on me so while i was digging around i found the thermostat up in the hose. i put it back in just like i would with a car. but i seem to keep having problems now. i put it back in with the arch up toward the radiator. runs find for a while but then overheats again. i tested stat in boiling water to see if it worked and it did. how does it go in. i liiked at my manual it looks like the stat goes in arch down. can anyone help me please. thanks steve