I think your best bet are the Felsteel helm and gloves. The helm has 12 more defense rating than the Righteous helm, and socketed with 3 solid stars of elune will serve you for quite some time, which leaves you with a bit more stamina and a lot more armor to boot. The lost spell damage shouldn't be too much of a problem, I never had real problems in Kara with aggro, since you can always use a wizard oil to more than offset what you lost.
The gloves, while having less stamina, have 11 more defense rating, and when I was still working on uncrushability, I socketed them with 1 solid star and one of those red +8 dodge rating gems, which gave me another 3 parry rating as bonus. These two items get you another 2.42% towards uncrushability then, which leaves you at 100.33.
Now I hope you have a druid in your raid, because GotW gives you another 14 agility. With kings, you'll be sitting at 155 agility, which gives you an additional 1.12 dodge over what you have now, so you'll be at 101.45, so that's less than 1% away from your goal.
Some people here said that the first few bosses won't give you much of a headache if you're just a little bit shy of 102.4.
And of course, if you have a shammy, he can drop GoA, and 77 agility, plus the kings bonus, give you a massive 3.36 to dodge, which will allow you to easily reach uncrushable.
Also, you should be able to tank the easier heroics now, at least if you have a priest or lock with you that can buff your health a bit more. You can also trade out gear for more stam, as long as you maintain 485 defense, since nothing in heroics can crush.
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