I don’t pretend to be all that informed about engine water temp. There are far more smarter guys here than me. I only throw offer my way as an option. reading what I could find here I liked the idea of using the temp at the block. My experience with my car is the temp gauge moves up to the center point when idling and then the fans kick on. While driving they do not turn on. However when I stop and turn off the engine they will often turn on after a minute or so and run till the block temp drops. I assume that air blowing over the engine helps cool. I don’t know if it is the optimal place but it works for me. 72 body and block, everything else 71, Tokico springs, Illumina, R180 CLSD, 83 close ratio, 3.90 gears, Ztherapy SUs, BRE 15X7 Libre wheels and BRE front spoiler.