[hound dog]

Yep, been there done that. Had a chrome thermostat housing and it was warped far beyond any manufacturers spec! Was surprised to find that the mating surface on the Edelbrock intake wasn't flat either. What a mess! Anyway, I took a large file and went to work on the thermostat housing and got it reasonably flat and reassembled with plenty of silicon sealant on both sides of the gasket and haven't had a problem since. Double check your sealing surfaces.
h dog