i just had my truck too for 6 months now and here's what i did: i changed the spark plugs, i replaced the pcv valve. did the fuel system thru a shop(got a better throttle response after and a noticable mpg gain) although i wish i did it myself and save a few extra bucks. did the oil change too myself. before i did all this i was getting 450-460k a tank now im at 510-520. then the modding starts
. hope this helps and good luck with your new truck.