In this old thread where we were talking about gauge senders:
http://67-72chevytrucks.com/vboard/s...d.php?t=714839
davepl shows a factory chart showing characteristics of the sender at various temperatures.
Is there similar documentation about the characteristics of the temperature warning light sensor? I realize it does not vary in resistance, and it just switches on at a specific (mystery?) temperature. I would like to find a sensor that switches on at the same temperature as the factory sensor for a 350 SBC, but with 3/8 NPT instead of 1/2 NPT so it fits in the new head.