i was checking my car's sticker the other day and i couldn't find where it said 3.55. so maybe i have the 3.31?

08 manual gt.

 

Look underneath your axle it should have a tag. Mine does it saids 3:55 though they have been changed to 4:10s'. Also I have to agree with Margarita Girl with the gears , CAI. tune and my pullys it's a pretty good combo. Really 4:10s' are perfect but you really don't have an overdrive gear but I like the way mine purs going 85mph at 3000 rpms.