Has anybody gone from 2.73's to 3.42's in here? How much of a diffrence did you notice? Any reduction in ET? Is it worth it? Also what is the diffrence in changing from a 2 series to a 3 series carrier? Does it cost more? Any help would rock thanks alot!

 

I've never done this but I can say that the 3.42s with a big converter is an awesome combo. Low 12s in good air, nasty punch at any speed, and 25 mpg on the x-way.
If you have a good 2 series carrier then there is no reason to replace it. If your posi is bad then get a 3 series carrier and matching gears.
hope this helps,

 

A 3 series carrier is for 3.XX and higher gears. Your auto has 2.73 gears and a 2 series carrier so you couldny use a stock 3.42 ring and pinion in that rearend. there are a few choices though. buy an aftermarket gear 3.73 is supposed to be the best for an a4, or a 3.42 thats made for a 2 series carrier. or you could use a stock 3.42 gear from an m6 car and buy a spacer. this isnt the best option though. I do have a stock 3.42 gear from my 01 Z in my room with 23,000 miles on it if your intersted. Other than this, you could do a moser 12 bolt/9 inch conversion. The nine inch eats more power, but theres more gears available...

 

I have richmond 3.42's for a series 2 carrier in my car. I moved up from the 2.73's and like them a lot. My only complaint is that some of the top speed is gone when I am out on texas world speedway, so now I keep it in Drive Great gears, but are quite noisy at first. After about 5-7k miles they either quiet down considerably or I am used to them.