Well I know I have a 4v but I love my 4.10's in my 5 speed. I have a buddy that ran 4.10's in his Gt with a 5 speed and loved them too. 4.10's FTW :beer::rockon::burnout:
If you have an auto then you have 3.31 stock so you can't go wrong with either. If you have a manual you have 3.55 so going to 3.73 would be a waste of time and money. Get the 4.10s. When I have my 06 mustang w/5speed man, I went with 4.10s. No regrets. The car was my d/d that saw 50 miles per. day on the hwy. I also to the car to the strip from time to time.