I have an EGT gauge on my manifold as well as behind the turbo on the exhaust. I have been told that the truck should cool to 300 degrees prior to shutting down. Is that 300 for the turbo or for the engine? After pulling hard I found that it takes a little longer for the temperature on the exhaust to go down to 300 while the manifold temperature cools to 300 fairly quick. After seeing this I would think that anyone with modifications really need two egt gauges in order to protect their investment.