Yesterday I took my pistol infra red thermometer to work and took readings while we were doing a HUGE job where we ran stationary for over 4 hours continuously. This is a normal duty cycle for us.
The vehicle is an old 06 GMC Savana 3500 with the 6.0 V8 and a coolant heat exchanger. The engine is running at 1500-1600 rpm and the load is actually pretty light as fuel consumption is 1.4 GPH.
Oil pan temp- 201* fahrenheit
oil filter- 211*
trans pan- 188
Driver's side converter- 455*
Radiator (top)- 178*
It's pretty obvious that our Factory Authorized upfitter has worked this out pretty well. This unit has 400 hours on it and over 180k miles, still runs like a gem...