If you are looking to get better MPG, dont turbo it. Yes the MPG will improve, but you will not get more MPG do to the fact that no one that turbos a truck keeps their foot out of it. Safe boost levels are all in the eye of the person behind the wheel. 10-12 is usually safe, in most cases. You will need fuel system, ie. fuel pump, injectors at least. Built trans if you want it to stay alive. And its not if you will break something its when .