Big decision time. I don't think it's wise to just call here and see what happens. What happens after a call is that the pot is bigger than your stack, which is more than 1/3 of the way in the pot. Villain will have two more streets to shove, and most villains probably will, so we shouldn't donate this $170 unless it's part of a plan to deal with the impending $455 bet.
All we really have to work with is a PFR/call from UTG and a check-raise on this semi-threatening flop. This line could represent a lot of hands because he's come out of the gate LAGgy, so it's not a simple range. He could have almost anything—an overpair, a set, two pair, the made straight, an open-ended straight draw, a pair and a straight draw, and probably a couple oddball hands that are hard to account for.
There are basically three routes you can take here:
1. Fold, if you really think his range overall has you beaten.
2. Shove, if you think he specifically has an open-ender. This is really the only draw you'd need to deny odds to. All other draws are very weak.
3. Call with the intention of calling all the way. This would be the best play if you think he'll shove for the remaining $455 after this check-raise, which seems like the play he's setting up.
I don't think #1 is the right play, simply because it's too possible for him to have so many unpredictable hole cards. There are a lot of ways he could have hit that flop. Some of them are super-strong, but many more of them are not. It's gonna sting when you find yourself paying him off, but that's one of the tough parts of playing against LAGs.
It's worth noting that an observant player probably would choose to slowplay a made straight here, given how nearly dead you'd be with an overpair or two big cards. Even a set may be a good candidate to slowplay. Why risk blasting you off the pot when he could let you hang yourself? You probably look pretty aggressive to him too.
I don't think #2 is a good play either. He could have an open-ender, but it's basically T7 or TJ, which is only a small slice of his range (and why not just call with one of those hands, against such a small flop bet?). Against the rest of his possible draws and weaker made hands, you want to take option #3. If you shove, you guarantee that he gets paid off on all his super-strong hands but give him a chance to get away with his weaker hands.
So that leaves #3: call now, and plan to call the probable shove on the turn. If he checks the turn, shove yourself.
