Donnie's GTS

american muscle sells a 4.10 gear kit for 500-600$ comes with oil, gears and a handheld tuner. Gears hurt mpgs they do not help.

FDNYBullitt

Going to 3:73's or 3:90's won't affect your milage that much, unless you always have your foot in it,but will definately wake the car up plus all you need is a speed-cal to cure the speedometer issue, good luck.

jbullitt2005

Hey man if your going to do gears don't do anything but 4.10's anything else is a waste of time if you wanted a car to get good gas mileage you should have got a prius or something. It will make it into a totally different car im telling you all you need is a chip or a tuner just to change the computer for your speedo, if you look around im sure there is a performance shop that will do it for you and unless there out to screw you it doesnt cost a lot unless you want to completly tune your car then your looking at more money.

ribo68

Change the shifter to a short throw, cai, and exhaust of your liking then gears IMO. I have an extra shifter if u r interested. Can't help w/ any of the other stuff. PM me.

DiZzyBonne

If you plan on getting blown in the future, get 3.73s. If you plan on staying N/A (naturally aspirated, as in noturbo or supercharger,) then get 4.10s.