Here's what it says

Something you may consider is changing the wheel & tire diameter. A good friend of mine drives a Ram with the 5.7 L Hemi. I drive a Silverado with the 5.3L / 3.42 rear end. He used to laugh at me, when we left rest stations both with trailers in tow. He used to run away from me while merging on to the highway. Recently, he put 20" rims and new tires on his truck. Now, I run away from him when merging onto the highway.

I'm not sure of your wheel tire combo, but you may consider putting smaller diameter tires on your truck. This would effectively change your gear ratio. Keeping the originals for when you bring the truck in for service wouldn't impact your warranty.