Villian is a conservative player - by conservative, I mean I have seen him lay down some hands. This is live $4-8. My image is pretty tight-aggressive and I had a mountain of chips in front of me - I think about $450.

I have in the CO and it is folded to me. I raise, he three bets, blinds fold, I call.

Flop: I check, he bets, I checkraise, he calls.

Turn: I bet, he raises, I fold.

Is this play worth it? My thought when he three-bet preflop was that he had a hand, this guy ain't three betting without JJ-AA or AK, maaayyybeee AQ. So my plan was to dump it on the flop without a set and then the all-heart flop came and I decided to try to make a play.
But which of these hands does a "conservative" player fold here? Does he fold KK with no heart? QQ or JJ?

This is limit poker. Even conservative players will call down and make you show your set/flush on an underboard. The monotone flop is actually more likely to make him call imo, since the odds of you being on a draw and not a made flush are decent. The only thing he might fold here is AK/AQ, and again, if he has a heart, he isnt folding those either which makes your bluff very expensive and not very likely to succeed.

Having said that, if you really think you could have got the guy to see monsters in that flop and fold, I trust gut reads live. Theyre usually right (but sometimes they're just hopeful thinking ).