Basically I know nothing about what axle or gears are in my stock 2005 GT.

I have an opportunity to purchase a stock rear axle from a 2009 GT500
(a 8.8" rear (3:31 ratio, posi).

If I were to go with this I would likely add a bigger gear also.

Is this a worthwhile upgrade? And does anyone know approx what the installation on this would run?

Thanks

 

I believe you have 331 in there now and if your going to change gears just change them in your current rear end and save some trouble. How much is the axle your looking at?

 

$400

 

Thanks, that was my biggest question of what in there now?
I would think that a Shelby would "at least" have larger gears in them?

I'm kinda surprised its the same rear end as a GT....

 

Actually all 05-06 mustangs came with 3.55 rearend gears, instead of 3.31. You would actually be down grading yourself.

 

Thanks guys!

I think ill pass....

 

No prob

 

V6 and GT500 have 3.31, GT has 3.55. GT500 has more power, so it makes more sense to use the gear for more top end. If they put 4.10's in it, then that would just make it even harder to get traction.

 

The only difference between the GT axle and GT500 axle is that the axle tubes on the GT500 are larger and maybe larger axle bearings. It's also factory installed in the '08 Bullitt with 3:73 gears. Other than that and gear ratio, they're the same. They even share the same rear brakes with the GT and V6.

 

fyi... 3.31 factory gears in 05 GT were standard. 3.55 were option in the manual tranny cars, IIRC

 

Good catch. Although I don't believe it was optional. 3.55 with manual and 3.31 with auto. This is like playing S197 trivia. Lol.

 

My 06 GT has a 3.31 sticker on the gear housing. Check for a sticker to know what gears you have. This is my next mod also.

 

That means you have auto...all manual 05-06 came with 3.55 standard and autos came with 3.31

 

fer shore