Ftyler,
If I understand your response: the 292 head has the temp sensor on the head, but the 250 has it in the thermostat housing? Does the 292 also use a different plug (5/8" vs 13/16")? See when I had my engine built, the passage on the head walls was so narrow, I couldn't use my standard plugs (socket wouldn't fit) so I had to find a 5/8" nut plug to fit in. Just curious.
Oh and Fleet, welcome aboard. These are some great folks around here.