Art161

Thanks for this info.

I think that the 3.55 was standard for a GT manual transmission prior to '07. The Workshop Manual was probably written before the 3.31 was made standard, and the 3.55 became an option. So it does make sense that the 3.31 LSD would have the same code, whether manual or automatic.

jz

All GT's have the LSD. V6's did not come standard with it, I'm not even 100% sure it was an option but it sounds as though you're looking for a GT so it doesn't matter. It was either 07 or 08 that the 3.31 became standard with 3.55 an option. before that 3.55 was the only gear available. But like other's have said there's a sticker on the pumpkin housing that says the gears ratio.

S197GT07

So you drove around at like 4200rpms the whole time?

Midnight Express

i know the 08's come with 331's. They suck i hate them. I want 373.

07vbluestang

this works for any car or truck. put a jack under the pumpkin. put a chaulk mark on the bottom of a tire and on the bottom of the driveshaft. spin the tire 1 revolution and count the number of turns the driveshaft spins per 1 revolution of the tire. ex: 1 revolution of tire and DS spins 3 1/2 times you got 3:50 gears, if DS spins little more that 4x you got 4.10.

cummins cowboy

I drove an 06 later today that had 3.55's I could tell a difference right away, to me it felt like a different car, the difference in gear was that much over the 3.31, who in the world thought these cars needed 3.31's, they were and idiot, with the 3.31's its just the wrong gearing I would imagine they would suck driving up a curvy road in a canyon as well, you need to use and feel the gearing.

hardcore302

starting in 07, the 331 was standard. i know this because when i went to buy my car, i asked them specifically what gears were available. she said that this is the first year that the 331 gears are standard, for better mileage, and you look like the kind of kid that would like 355s. i said yes mam you are not mistaken.

Diabolical!

In '05 and '06 all autos came with 3.31s and all manuals came with 3.55s

From '07 until '09 all GTs came standard with 3.31s but you could order the 3.55s as an option if you ordered a manual transmission.

3.55s were never available on the automatic.

All S197 GTs are limited slip.

BruceH

3.55's were a $300 option in 2008. I wouldn't sweat the gearing too much, chances are you will have them changed at some point.

Diabolical!

Damn, they went up to $300? They were only $100 in 2007. That's a rip off when you consider that all they do is install a different ratio on the assembly line. The materials and production cost between a set of 3.31s and a set of 3.55s is identical.