... that is where I am running mine now. I heard people talk about how the dash temp gauge is typically off because of age related things but I used a fluke infrared temp sensor to check the intake sensor and the gauge sensor in the head and they both were reading correctly, but the intake one was almost 20 degrees less. Since this is being used for fueling and fan operation, should I move the ECM sensor to the head?

I also got a new reverse poppet 190 thermostat installed. It is for a Hummer cause it was one of very few that I could get in that temp. It took a little grinding of the perimeter and I ended up using a summit o-ring style housing cause the stock one didn't fit. ANYWAY, the bird is running much healthier now that the 180 is out.

 

Possibly ,but the factory was happy with it in the intake.
How do you explain the temp difference?
My logs show the CTS temp within 5 degrees of what is showing on the temp gauge

 

Because the CTS is the actual temp reference for engine control it's the temp gauge that's 20° more than the CTS. The ECM doesn't need the temp gauge which is solely for the benefit of the operator.

 

I am thinking that maybe running Aluminum heads and intake may be the cause for the difference. Stock everything is cast iron, and with the Al heads being able to dissipate heat better, maybe there is that much difference in heat loss as the coolant passes from the heads to the intake.

Either that or the heat from the headers is heat soaking the gauge sensor. I'll play around with it more today and get a chart for comparison.