The hole in the thermostat is great for removing air from the system however if you want to prevent damage when the thermostat fails get one of the new ones that fail in the open not closed position. These things are a life and an engine saver.
"If it ain't Steel it ain't Real" "Earth the insane aslyum for the rest of the Universe" 41 1/2-ton, a work in progress 68 Shortbed stepside 327/325hp/700R4
