1970 Duster project in Sweden

suggest that you get a thermostat gasket from Real Gaskets in Tennessee. I've tried other gaskets of theirs and was underwhelmed but that thermostat gasket is great. If you get one FOLLOW THE INSTRUCTIONS. I have one that I have used in a motor for 3 years and I needed to remove the housing twice. I followed the directions and reused the same gasket and it has never leaked.