Noob Question

[BlackLT1Z28]

I pretty much know my way around a car, but knowledge of rearends apparently has eluded me, so I have decided to start learning more about them. I know some basics but not as much as I want to know. I looked at the sticky threads, but couldn't find an answer to my question. So here it is...
What exactly is weak about the stock 10 bolt? Is it 1 specific part, or is it a combination, or is it the whole thing? What exactly breaks for people? I am asking this because I am going to be getting rid of my 94 Z in favor of an LS1 WS6 and don't want the rear to break on me. Thanks.

[MYHAWKROCKS]

There is a few things wrong with 10 bolts, not just one specific part...they have a small diameter pinion and gets smaller, if say you install some 4.10s, axle size/ spline is limited due to housing size, bearings are small and don't offer much support, stock posi wont last long with agressive driving, and c-clip axle...so they have issues and would be best to keep in mind that a 12 bolt would be a good investment