So, I have a 2004 Durango AWD with the 5.7 Hemi and 270,000 miles on it. I've owned it about 2 years and to say it has been a great vehicle is an understatement. Recently I discovered that I have a slow leak of coolant into my oil, and I caught it starting to overheat few weeks ago. I'm guessing it is the head gasket and am preparing to pull the heads and replace the gasket. While I am in there I'm planning to do the water pump, timing chain, timing pulleys, all my coolant hoses, all my belts, and anything I see in the process that needs changing. What I'm wonder is, what can I possibly do while I have everything broken down, that can help me with any or all of the following 1-gas mileage 2-horsepower 3-torque Not trying to make it some sort of super SUV or go all crazy, just figured while I have it broke down why waste the chance. So any ideas?