It all depends on how your threat is at the moment.
If you're having absolutely no issues with threat, and feel confident that a drop in your Hit would not result in loss of drastic threat, you might benefit more from the raw +24 Stam gems in place of Hit/Stam.
Weigh up the cons and pros - how much actual health will replacing the gems give you? Is that ammount of health worth it?
If I had to throw down a Yes or No answer here, I'd say Yes.
Edit: Also, your current health pool is quite nice, so if you decide to stay with the Hit gems due to Threat, you still have a nice bit of Health to go on.
Hope this helps