Jordan123

More gear is not always better not just the dd or gas milage but with gts they dont make good power in upper rpm range. I used to have 4.30s and it had a good 1st and 2nd but then fell on its face in 3rd because it was kicking me out of my power band. So with out cams or something to help the higher rpms i would stick with a 3.73 or a 3.90. i switch from 4.30s to 3.55s wasnt quite happy then went to 3.73s and this is what it will stay.

teej281

4.30's are probably a little bit much for a bolt-on gt since we dont have the upper range that a 4v does, but thats why they say 4.10's for GT's and 4.30's for 4v's. 3.73's, in my personal opinion only belong on fox bodies and cars that need more gear for the 1/4. My car is a street car so even if it got a blower it would still get 4.10's. only way i would do anything less than a 4.10 would be for turbo and that would be either 3.73's or 3.55's.

Dteal23

go for the 373's. there are people here that will tell you some retarded *** **** like 373s are for b!tches ect, but i say go for it

Eagle2000GT

The OP has a 2006 GT. I wasn't that familiar with the car so I did a little research. If google is right, the wheel on the 2006 GT is bigger than the ones on our cars. It is approximately 27.25" in diameter (about 6% difference in circumference). Couple that with a T-3650 transmission and I'd have to recommend 4.10 gears. The bigger wheel waters down the 4.10s so that it would be similar to running 3.90s on my car through the first four gears. With the T-3650's .62:1 fifth gear ratio, the OP would probably be driving down the highway at a lower rpm than I am with 3.73 gears.

There are a lot of variables in deciding which gear is best. In this case, I recommend 4.10s.

Edit: Have you noticed that some of the newer cars are coming from the factory with 3.73 gears. They are also running 19" wheels which completely waters down the gear.

boomee

Look there seems to be a hundred forums on the whole 4 10 or 3 73 argument find a freind that has the 410s see if you like it then make your own decision everyone here is gonna have an opinion but you will never know if its wright for you unless you drive it

stangpilot08

LMAO! I had to read that post twice to make sure it wasn't a spanish translation...

teej281

not only does the 05+ have bigger tires...but they also have a better powerband. So...i stick to my guns and will stand up to the firing squad we got going on here and say 4.10's.

Jordan123

i didnt realize it was a s197 yea i say 4.10s

stangpilot08

I wouldn't say that if there is a plan on going F/I in the future.

teej281

I would...the larger tires gear down the gears. I'd run 4.10's with all boost but turbo on a stock sized tire for my car. Just have to have the right tires and the right suspension.