Trailbeast:
I know what you mean about the orange silicone. My new Chevy van came with leaking valve cover gaskets and that's how the dealer repaired them. Never leaked again in 13 years.
I did use a silicone sealant on the t'stat housing, but the leak came up around a bolt head (sealant was also applied to the bolt threads). Those bolt holes look like they do not go into the water jacket, but I wonder...
