don't know how i missed this before:
https://rennlist.com/forums/996-forum/827720-oil-temp-gauge-using-the-built-in-oil-temp-sensor.html
i'd looked into using the oem temp sensor to drive a gauge, but once it got beyond using a voltage divider circuit i gave up and went to a seperate vdo temp sender instead. as noted in the linked thread, this sender is not located in the best spot.
any chance fred can get a few of these arduino boxes fabbed up?