okay, this one is a little bogue but it IS data.  maybe noisy data 
but we live in a noisy universe.

I just replaced my thermostat when i did head gaskets on the '87.  previously, 
the water temp gauge was always smack dab in the middle of the red 
warning LED.  now it is running completely off but adjacent to the LED on the hot 
side of the scale.  heater output is wonderful but i'm wondering if i 
still have some entrapped air causing the system to run hot.

my '85 ran on the LED even after i replaced the thermostat.

i realize these gauges are not an accurate nor precise measurement 
and that there will be van-to-van variability. but....

i think this replacement thermostat was an "87" as was the one that 
came out.  that's 188.6F for us colonial boors.

inquiring minds sorta need to know.
-dan