I am leaking Anti-freeze from the where thermostat housing and cylinder head meet. My father-in-law told me it was the thermostat housing gasket that was leaking but i can not seem to find that part anywhere. The only thing that i can find that is similar is a thermostat seal. this is just a small white circular piece of rubber not the traditional rubber seals that I have seen before. Can anyone tell me if this is the correct gasket or is it some special order part? It is a Fel-Pro Thermostat Seal part # 35588. Thanks.