Does anyone have access to an NHC-250 installed in a civilian truck (not military surplus).

I'm working with an ex military M923. The military routing has coolant running through the radiator, bypassing the thermostat, at all times (the thermostat still works, there is just an amount of coolant flowing anyway due to other hoses). I'm trying to figure out if it was just their solution to making the truck usable if the thermostat failed or something cummins did. I want to find out what the civilian trucks did for coolant routing so I can see what I can do with mine. In other words, if those trucks don't bypass the radiator, I'll set my truck up the same way. A truck that you can't even get warm during summer makes it tough to have a heater in winter!