Temp sender location is all relative. All you want to make sure of is that there is some liquid flow over the sender so you can read changes. Don't want to put it in a dead spot. As far as the temp itself goes, trying to pick the hottest or coolest spot isn't that important - as long as those areas don't exceed the fluids capabilities. My oil temp sender is in my drain plug. Lots of flow over that area, so I can read changes easily. I like running with oil temp between 180 and 200. The oil I use can easily withstand temps over 250. I am way safe. More interested in consistency for the run.