WSOP Main event hand 100/200 level

[HEK]

I have 33k to start the hand
EP guy has 21kish to start

I raise to 600 UTG with AQo. Guy 2 to my left calls, button calls. EP guy has been playing tight, seems much more concerned with surviving than playing well (weak/tight). Also, my inclination is that he's a half decent hand reader for this field of donkeys.

Flop (2100) 7 3 3 r

I bet 1400. EP raises to 4k. button folds.

I raise to 12k.