I have done the thermostat gasket 4 times. I have gotten a new housing, various brands of gaskets, a new thermostat, and blue RTV on both sides every time. I have followed the instructions for the RTV drying times exactly, keeping it completely dry while drying. I have cleaned he mounting surface on the intake manifold with wire wheels, steel wool, razor blades, scrapers, brake clean, ect. This time I thought I finally got it because it hasn't leaked a drop in 5 days. Today was the first 80 degree day of spring and i went from 0 to 50 without really letting it warm up. When I got home I found it was leaking again, and sprayed all over the engine bay like usual. The temp gauge has always got to about 200 on warm-up then dropped and stayed at about 150, even before the leak. I really don't want to put stop leak in there but I'm getting desperate. Any ideas what could be going wrong?