Cutecriminal143, I will be the first to disagree with you, I have a 04 with 4:10's that I put in myself and it is almost perfect. Before the gear swap the most I could get out of a full tank was 320 miles, after 4.10's I still can get 320 miles. Highway mikes dropped 2 but city mpg went up 2. Every time I get in the car I redline it every few minutes. Gear up and drive hard!
2001 1/2 and up have a 3650 trans, 5th gear makes 410's GREAT on the highway, t5 trans maybe I would consider 3.73's like I did in my 88 5.0, my 04 if I ever take the rear end apart I will put in 4.30:1