i am not a mechanic so bare with me. What is the stock on an 05 and what does the 4.56 actually do. I understand that it helped you pull better but how? You say it didnt increase the the mpg but did better pulling. I guess I dont understand in my simple brain how more power/axle spin gives you better pull with same mpg. Is that something that is better for just hauling or daily driving? I guess I am just wanting to know how its better then stock.