Carl, dt = Dave T
IIRC it's a Robert Shaw thermostat and yes it has a small hole in the cover plate which would allow air and/or coolant to pass through it when closed. I imagine it came that way from the factory.
Ironically Robert Shaw used to have one of their factory/plants here in K-ville over by the university. That thermostat was probably made there and it's been in the 216 since at the least 1969 as that was the year it was parked and slept until I awakened it a couple yrs ago.
re. Volunteers, they're picked to win the SEC east this year, been along dry spell.....
