Oil temperature gauge for an M110
 

Hello all,
Has anybody had any experience of installing an engine oil temperature sensor in a M110? I am looking at putting a gauge into my 280SLC, before going into a semi-motorsport event in late October. Trawling the web there seems to be a few arguments about where to put the sender. Some say that it should be in place of the oil drain plug, some say the return pipe from the oil cooler. Or is it possible to take the feed at the same point as the standard oil pressure gauge pipe with a T-connector? Also, what is the usual oil temperature for the old M110?.. Any help or links would be most appreciated. Thanks!