re: "...87 on all three of my cars has the needle at the 9 o'clock position, with compensation board functional...."

Well that's the problem. The compensation board makes the gauge lie. Only by bypassing or disconnecting the board will you get a true, real-time reading of your temperature. The compensation board was put in (only in the USA, curiously) to keep owners from seeing fluctuations -- it tends to keep the temperature indication erroneously at 9:00 regardless of the real temperature; only extremes of temperature will show up (and rather suddenly) on the gauge by some variation from 9:00.

In other words, your reassurance that you're at 9 o'clock is not trustworthy, because of that board.