4.10 Gears and coustom tune ??

[04YELLOWGT]

Im getting this done monday and was wondering how much of a gain ill be getting. Its a tune he's doing with a Xcal. 2. I also was wondering how much time this will take off my 1/4. My car is an auto 04 GT and is stock except for these things. Also I heard it lowers your over all top speed but how though?

Thanks
RJ

 

[wannabe2000GT]

should be about .4-.5 faster in the 1/4. not sure about the top speed might be a bit slower but i v heard on here with the increased gear ratio it has more power up top but who knows.