[Branman]

Originally Posted by Faramir

There are a lot of "nutted" hands in your range, which he cannot fold out. (A2, A5, AJ, AA, JJ 55, 22 QQ, maybe bd hearts). And QJ would be bad since you would check behind all marginal hands, and you really have one ofthe nutted hands and wouldnt fold them or air. (so calling QJ would be optimal)

So i think he has a nutted hand himself that beats all of those hands. The problem is :I can only think of 4 hands here (KhTh, that didnt barrel turn to not get raised of, a weirdly played 34s that didn't barrel, or some 5h4h combo (pair+gutter+flushdraw) or maybe he has JhTh (since you appear to call flop donkbets light.)

Concluding: there are 2 things to say: he cannot move you off the nutted hands, so he shouldn't bluff here too often and only valueraise straights and flushes here.
But he can be on tilt, so he might not take that in consideration and do something stupid (maybe even with Khxx as blocker for the nuts), or make thin turncalls (with naked fd) to win it all back?. While his line is only congruent with KhTh and JhTh which is a really thin valuerange.
Up to you if he is so tilted that he can do some stupid things, or is thinking clearly and really has it.
Any timing/sizing tells? 2340 seems a fancy bet, which is usually made with nutted hands... since while bluffing he wants to look solid (like 2400)

Faramir said almost everything I thought of, however, I would add in that he can possibly be going for thin-ish value with 55 and an extraordinarily rare 22 since he should know that you recognize that it's very difficult for him to get to the river with straights/flushes. Additionally, he should know his range can't really include broadway sets given the HU 3b dynamic. So if he reasons that you will be obligated to call with two pairs then his value range is the weird broadway combodraws and the aforementioned sets and at the very thinnest, a theoretical AJ (however those combos have to be cut down since he checkraise/check calls that hands frequently and ditto the low sets). So I think this comes down to how often you've seen the villain turn made hands into bluffs and the X-factor of how tilty you think he is. I hope that isn't a copout of an answer but I just think these less tangible variables are the most crucial in this spot.