I'm responding to your question with a question in kind........
What is the value of each to you?
Just follow me here for a sec. If you swapped out gems for example, without altering CTC, let's say..... you were able to replace 4 gems with +60 stam gems.... what are you really gaining?
Last I checked, the value of those gems would equate to a +240 stam boost. Heck, even if you were able to put in 3 JC +101 gems and a +60.... you're gaining only +363 stam. I don't think CTC tanks have any stam modifiers like blood DK's or bears, so.... you're only gaining anywhere from 2400 to 3630 health.
That's.... not much. Sure, it gets compounded some with buffs, but I don't see you gaining much more than 5k health out of the bargain. Total. And health totals for a raid buffed tank are such nowadays that a 5k difference isn't really earthshaking. Between a 200k and 205k tank..... give me the one that will take LESS DAMAGE.
Consider applying some of that to avoidance. If you can reduce the amount of damage coming in, you'll come out ahead.
Or, maybe even consider gemming for strength. Better threat, small bump in damage output.... and actually a slight improvement to parry on top of that.
I just wouldn't go mad gemming for stamina with the return on that investment being so marginal.
No one tanks in a void.........