Been thinking about this some more. You temp sensor is located such that the sensor is directly in the water. The fitting is a plumbing pipe fitting meaning the thread is tapered. It would only need ~20 ft lbs to tighten a plumbing fitting. So why do we need so much torque to get it off? The corrosion is on the inside of the manifold. When you try to take it off your pulling the corrosive metal fragments that are coated on the pipe threads up and out the female connector. It won't let you do it. The long and short of it is, I recommend having the intake put in acid bath (tank it Dano!).
Tell em you want the fitting off. They will know how to get it off. If your having that much trouble getting it off then the guts of this part could be very poor. Tanking will destroy it or fix it. If it's weak, let it fail now.
