Truck won't come up to operating temp after rad install

[samckitt]

Originally Posted by Sieg

What is responsible for your temperature readings?

As Todd noted you may have went overkill on radiator size.

Would it be possible to slow or reduce flow to the radiator via water pump speed, impeller design, inlet/outlet reducers?

Unless I am missing something,
Regardless of radiator size, water temp inside engine should be at the temp that the thermostat is rated for. It will not open until temp reaches that value. The thermostat is your flow reducer.