The simple reason you broke it, as the others have said, is you were running the suspension constantly at full droop. They snap easy at full droop and you were forcing it there 100% of the time
You are in for some more surprises if you keep it up, but I let you discover those for yourself. You aint no pioneer, put it that way.
585 is the upper end you should run for best travel range, without putting on badly designed thai suspension kits that include diff drops and UCA's and more. (BTV, ZAWs etc) No one makes these in australia. They will also be illegal and make your car roll over easier.
No idea why people run above 32's & a 2" lift (other than to be a show off mall crawler) as I can get wherever a 35" shod, 6 inch lifted thing (of any make) can get anyway.
I have trouble understanding why you believe a CV should last a certain amount of km's...
It lasts as long as you allow it.. ie. stop punishing them. You want "problem free motoring.."? Stay at home and wash it.
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This is how easy they go at full droop with a little too much power applied and the front locked. (NB: you would not even get this far without a front locker - they are the people parked up watching & taking video)
http://imageshack.us/clip/my-videos/844/qxc.mp4/<clicky You get full droop whether you have a lift kit or not. So stop thinking a 2" kit increases your chance, it makes no difference. All you did was push it hard against the bump stops constantly.
I do not have a full lock breaking a CV video yet, but they smash the cups to a squillion pieces. Avoid full lock and too much power.
You can even do two at a time if you are really talented, so I have heard.
Power application (too much of it) kills them, but sometimes you need momentum, depending where you are trying to get. (this applies to front locked and open diff)
From what I have seen you do pretty tame stuff? So your CV's will last forever now you have reduced the height to a acceptable one.
//I have killed some in my time...
They are piss easy to change and I consider it par for course, and part of the fun.