Stars 33/5K...Top Set on River Facing Shove....Barf Again

[erc007]

PokerStars No-Limit Hold'em Tourney, Big Blind is t30 (9 handed) Hand History converter Courtesy of PokerZion.com

CO (t2265)
Button (t3555)
SB (t2810)
BB (t2855)
Hero (t2780)
UTG+1 (t2795)
MP1 (t2745)
MP2 (t3155)
MP3 (t4000)

No significant reads on villain. He's got a decent ROI in SS MTT's. My thought on the river was to bet/fold, but then I wondered if he would shove hands like 33;AQss for value? I was pretty sure that he wouldn't check a 4 behind on the turn and 55;66;77 will always raise this flop right?

Does the fact that I made a set here really give me any more showdown value/equity vs. his range, or am I still just beating a bluff?

Preflop: Hero is UTG with A[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/spade.gif[/img].
<font color="#CC3333">Hero raises to t120</font>, <font color="#666666">4 folds</font>, CO calls t120, <font color="#666666">3 folds</font>.

Flop: (t285) 5[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets t225</font>, CO calls t225.

Turn: (t735) 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, CO checks.

River: (t735) A[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets t335</font>, <font color="#CC3333">CO raises to t1920</font>, Hero...?