40mg of 2C-I and 60mg of 2C-B separately would be large doses, but would pose no dangers. Combined, that's a whole lot of 2C-X, and 2C-I and 2C-B are not the very safest ones. I would be wary of trying this. Just because there are reports of 100+mg doses on Erowid doesn't mean they're not going to do any damage. Most of those reports are about accidental dosages and the people don't seem keen on repeating those experiences.
The actual physical dangers are mostly unknown, I think. 2C-B raises body temperature and both 2c-B and 2C-I raise heart rate, so they could be dangerous in that way. 2C-E (not the same I know but related) has been reported to cause chest pains in some people even at much lower doses, which would worry me. Obviously the 2C-T-Xs should never be taken that high, although they're a bit different in that they're more physically dangerous.
That's all I can think of... I hope it helps you. Personally I wouldn't take doses that high but I'm pretty sure you won't die or anything. Out of curiosity, how high have you taken doses of these in the past? What has been yoyr highest combined dose, or single dose of one of them? If you've taken like 90mg combined before and not been worried about the symptoms, then you're probably okay. But if you've only taken, say, 60 or 70mg before, then please do not jump up so high all at once... work your way up for safety's sake. You can always take a higher dose the next time, and a higher one the next time, and so on, if you're not satisfied... but you can't un-take any dose, and safety should definitely come first, both for your sake and the sake of the community.