I have a stock truck also and I use the max Energy Programer from Hypertech.
It has been a great fuel saver for me, and you also get pulling power as you can tow on all power levels.
Today I towed stock and got 9MPG and shifted to level 3 and was easily towing my 15K RV at 14MPG.
Not bad for a $379 investment that also protect the truck while towing.
I also have the 6 speed and its a great MPG performer and even greater programed up to additional 114HP.
But the scangauge can teach you how to drive the truck economicaly.
I increased mine by added an SCT live wire, 4" turbo back exhaust (no kitty) and most of all stay out of it. with just the bolt ons i did I got about 1.5-2 MPG increase. not a lot... but it added up on my 10k lb truck.