I want to change my gears, have two questions.

**Cronex** · 03-27-2008, 02:19 PM

I have an A4 Trans Am with 2.73's installed from the factory. (I bought it used w/ 22K.) I want to change the gears to 3.73's but was wondering. Instead of getting the 12 bolt Moser rear with them, I was thinking of just getting the 3.73's and installing them into the 10 for now but was wondering if I would have to change the carrier too. I know in the older GM's you had to. But you didn't with the Fords. Is it still the same? Also does the 10 hold up good with 3.73's in them? All thats done mod wise is cat-back Loud Mouth 2 D/D, and I am either getting headers before or after this.

**Silver Streak** · 03-27-2008, 02:23 PM

Well.. for one.. you either have 273s or 323s.. but since its not a WS6 its prob 273.. anyway.. I did 373s in my 10 bolt for like 8 months or so before I stripped the spider gear and went with a 12 bolt. Dont have to change the carrier.. just make sure you get the gears for the carrier you have.. there are 2...

**Cronex** · 03-27-2008, 02:33 PM

I do have 2.73's. Don't know why I put 2.42's. But how would I know which carrier I have though? Is there an RPO, or a cast number, or what?

**Silver Streak** · 03-27-2008, 02:35 PM

I can't remember.. but I wanna say the lt1s had a 2 channel and ls1s have a 3 channel or something like that.. youd have to ask around.. this almost 2 years ago...

**Cronex** · 03-27-2008, 02:39 PM

Oh ok, well thanks for the info. I appreciate it.

**Silver Streak** · 03-27-2008, 02:40 PM

Np.. good luck...

**bgable** · 03-28-2008, 12:25 PM

I'm pretty sure you'll need a 2 series carrier since there 2.73's

**mghawk57** · 03-29-2008, 12:44 PM

I maybe opening a can of worms here,but I thought the Trans Am option came with 3.23 as standard with the A4.I did not think the 2.73 was a option for a Trans Am.I know about the option codes,but something seems fishy.CRONEX if you have the last eight in the vin # I can see what the factory says.

**Silver Streak** · 03-29-2008, 01:02 PM

Originally Posted by mghawk57

I maybe opening a can of worms here,but I thought the Trans Am option came with 3.23 as standard with the A4.I did not think the 2.73 was a option for a Trans Am.I know about the option codes,but something seems fishy.CRONEX if you have the last eight in the vin # I can see what the factory says.

273 was standard on trans am 323 was an option.. 323 came standard on WS6.

**Cronex** · 03-29-2008, 07:25 PM

Mghawk57, 2.73's from the factory is legit. I already knew this, and posted about it in another thread titled Gear Ratio. You can check the RPO codes on the drivers door, no need to check the VIN #. Also, as Silver Streak pointed out 2.73's are the standard for A4's, RPO code GU2. RPO for the performance option 3.23's being GU5.

**Cronex** · 03-29-2008, 07:45 PM

...forgot to add. If you check on Texas Speed's website under 98-02 F-Bodies both Motive and Ratech sell gears for a 7.5 GM 10 bolt rear with a 3-series carrier. If you check SLP's website too they also sell gears for a 7.5 GM 10 bolt rear with 3-series carrier under 98-02 F-Bodies. So it is a 3-series carrier, they also put them in S-10 trucks too.

**GatorSS** · 03-30-2008, 03:04 AM

If your original gears are 3.08 or less, you have the 2-series carrier. So, those A4s with a 2.73, you have the 2-series. For those A4s with a 3.23, you have the 3-series.

**mghawk57** · 03-31-2008, 03:43 AM

I guess I'm still not making my point.I thought the Trans Am option was upgraded to 3.23 gears as part of the Trans Am package.Maybe you can delete this and get 2.73.But I sure don't know everything I guess.

**Silver Streak** · 03-31-2008, 08:08 AM

Originally Posted by mghawk57

I guess I'm still not making my point.I thought the Trans Am option was upgraded to 3.23 gears as part of the Trans Am package.Maybe you can delete this and get 2.73.But I sure don't know everything I guess.

323 was part of the WS6 package.. but was an OPTION on the base Trans Am... otherwise it came 273s standard (for autos).