EGTs and Gauge

[NDISX15]

Cruising at 68 in 18th empty with the cruise on im between 500-680 on the highway with rolling hills. Interstate at 75 is slightly cooler, but the difference lies in each truck is different. Im 65k empty with trailer, and running a 540/1850 tune on my motor that was 450/1650 stock. More fuel means more heat, but yes, my probe is against the inlet tube. Grossing 140k in 17th at 60-65 with some rolling hills and a couple short pulls it seems like im around 750-850 avg....and sometimes depending on my momentum im seeing 900 but when I hit 900 im turning on the engine fan to cool off on a pull or I just drop an extra gear and let it walk up the hill.