value bet set on 4-straight board?

[medicated]

villain is 15/4.6/2.8 over 600 hands. do you value bet the river? if so, how much? feedback please on my line as well. thanks!


Full Tilt Poker, $1/$2 NL Hold'em Cash Game, 9 Players
LegoPoker Hand History Converter

SB: $201
BB: $266.60
Hero (UTG): $348.80
UTG+1: $98
UTG+2: $231.15
MP1: $94.85
MP2: $222.25
CO: $197.25
BTN: $1,209.05

Pre-Flop: 8[img]/images/graemlins/club.gif[/img] 8[img]/images/graemlins/heart.gif[/img] dealt to Hero (UTG)
<font color="red">Hero raises to $8</font>, 2 folds, MP1 calls $8, MP2 calls $8, 2 folds, SB calls $7, BB folds

Flop: ($34) 8[img]/images/graemlins/spade.gif[/img] 4[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/spade.gif[/img] (4 Players)
SB checks, <font color="red">Hero bets $20</font>, 2 folds, SB calls $20

Turn: ($74) 5[img]/images/graemlins/heart.gif[/img] (2 Players)
SB checks, <font color="red">Hero bets $50</font>, SB calls $50

River: ($174) 6[img]/images/graemlins/heart.gif[/img] (2 Players)
SB checks, Hero ?????