xxkazp3rxx

I have driven GT's with 3.73, 3.90 and 4.10.... 3.90 is a step slower then 4.10 out of the hole, a lot quicker then 3.73 out of the hole... 3.73 have more up top, 3.90 and 4.10s are equal from 2nd to about mid 4th.. you pull harder in the middle/top of 4th with the 3.90's over the 4.10s.

If you plan on staying N/A - and dont do a ton of highway driving - may want to look at 4.30s... Not a bad option. Personally, I really don't like the 4.10's, If I had a GT and was staying N/A - i'd probably do 4.30's in hindsight, with some sticky tires, haha. I planned on FI, so I put 3.90's in my car, and will probably do so in the Cobra.

mustangman02232

4.10, 20+ mpg on the highway still

contentsunderpressur

My car has a supercharger and 4.30 gears and i'm tellin you there is a lot of shiftin goin on in the 1/8. I wish I would have went with a 3.73 or 3.90. I'm in fourth when I cross the line in the 1/8.

lizzyfan

So does that answer your question?
It's all up to you!

xxkazp3rxx

4.30s and a blower... dang you're one crazy mother! lol.. hope its not your DD.. I cant imagine first gear on that thing, lol

contentsunderpressur

Yea, my gas milage is now 18 mpg and I shift to second before the 60 ft mark. I had no clue it would be like this when I had the gears put in.

ben790450

If you're going s/c man id go 3.90s. 4.10s is going to be too much for an FI project on the street.

PushinTheLimit

Just to give a point of reference, the 03/04 supercharged cobra's have 3.55 gears. Usually guys don't bother changing the gears in them cause it seems to work well with the forced induction.Some guys change them out, but really sticky tires are needed for that. Since your auto, 2V, and do some highway driving... I would 3.73's would work well for you. Its still a matter of opinion but just my 0.02. Does Ford Racing make the 3.90's? I thoughtfor some reason they didnt.

ben790450

Dude go with 2.30's. Youll get awesome gas mileage and your top speed will be somewhere in the mid 200's!

mustangman02232

actually, i think that with decent rubber and some suspention work, 4.10s and a centri will be fine, if theres crap stock tires and no suspention work, you really have to feather the throttle

dan has them in/for his cobra[&:]