One other thing.....my car is at 1800 rpms at 60 mph, and even before i get new tires i would like to swap out my gears, because i have to kick down at a grade maybe 2 or 3 percent......the 4.7 doesn't exactly hop up the hills. would you recommend the 4.10 gears, and where would I find them? I don't know what to look for....