There are still a lot of 444's running about Australia BUT there is a few mods you need do to have them working hard in 120F + weather --- The STC oil supply come from the Camshaft oil gallery and caused a lot of Cam bearing fails -- Need to tap into the test point on the back of the oil pump to supply STC (This was a Cummins Fix). If you have the original optomized aftercooler system with the weird radiator with 1 and a quarter inch radiator hoses both going into the headder tank on the radiatorand then chuck out the thermostat that prevents flow coming into the block (keep the other one) With these fixes you will have no worries. I have one myself never seen the temp gage above 190F even pulling 90 ton up 9% grades. Most 444's do about 1 million miles and then take a rebuild if you work it hard but look after it. Also best to add a couple of thou to the valve clearances if running in hot weather.