4.6HighPerformance

hi all, last time at was at the track my auto 2006 mustang gt ran a 13.7@101.43 on stock tires.... thats with intake, headers, and x-pipes. now recently i had 3.90 gears installed and it was custom tuned... how much time more or less did i shave off of my 1/4 mile time?????? im just looking for a ballpark figure... and i imagine with slicks, or drag radials it will improve even more... any help is greatly appreciated...

thanks.


tony