Strange hand.

Opponent seemed loose-passive / lame. What do you put him on, and do you fold or call the river?

PokerStars No-Limit Hold'em, $4 BB (9 handed) converter

CO ($606.55)
Button ($414.40)
SB ($459)
BB ($554.45)
UTG ($646.15)
UTG+1 ($406.90)
MP1 ($347)
MP2 ($1264.75)
Hero ($529.75)

Preflop: Hero is MP3 with 8[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/spade.gif[/img].
<font color="#666666">2 folds</font>, MP1 calls $4, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $16</font>, <font color="#666666">1 fold</font>, Button calls $16, <font color="#666666">2 folds</font>, MP1 calls $12.

Flop: ($54) 6[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
MP1 checks, <font color="#CC3333">Hero bets $24</font>, Button folds, MP1 calls $24.

Turn: ($102) 9[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
MP1 checks, <font color="#CC3333">Hero bets $56</font>, MP1 calls $56.

River: ($214) 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets $64</font>, Hero ???