Just an FYI for all of you guys that have a 6.8L engine in your newer John Deere Tractor. My father-in-law has a 2011 JD 7330 with the 6.8L engine and 155 factory HP. It's out of warranty and he wanted a bit more power to run the field finisher and disc so he called our local JD dealer in eastern Iowa. They came out and turned it up 40 HP with their computer. Holy lord does that make a difference especially pulling hills with 600 bushels of corn behind it! So if any of you that have the 6.8L and are wanting more power, do it! You will be happy that you did! I know the 6.8L in some of the higher end 7 series had up to 200 HP, so it won't harm anything. Just a different computer tune. Doesn't seem to use much more fuel either.