Rear Gear Question

I was just wondering what the difference is in the rear end between a car that came stock with a 2.73 gear and one that came stock with a 3.23 gear. Besides the fact the 3.23 accelerates faster. I always hear the cars that come with the 2.73 as 2 series gears. What are cars with 3.23s and higher called? If a car came with a 3.23 stock is that rear end stronger or weaker than the car that came with the 2.73. I was just wondering because I have a 98 A4 with 3.23 and Ive got some basic bolt ons but the car has almost 70,000 miles and I dont want to snap the rear end at the track and I can't at this point afford a new rear end. My friend who has a 00 Z with A4, stock it had a 2.73 but changed to a 3.23 snapped his rear gear at the track in the burnout box. He had heads, cam, converter, and bolt-ons with a set of ET streets, and his car had only 22,000 miles.

The larger gears are called 3 series carriers.

As for breaking your rear, I think you should be just fine, the A4 puts a lot less strain on the rear than the M6 does. Also if your running regular tires and those gears you should be ok.

A little extra safty would be to get a Rear cover, they are cheap insurance but make it stronger, also some LCAs aren't a bad idea because they will eliminate wheel hop, and wheel hop is not too friendly on our rear ends