Donkbet this river?

[DCWGaming]

I rarely ever donkbet, but saw an opportunity that I probably should have taken. Thoughts? (opponent was 54/16 over 120 hands)

Party Poker 5/10 Hold'em (6 max, 6 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

Preflop: Hero is BB with 9/images/graemlins/club.gif, T/images/graemlins/club.gif.
<font color="#666666">2 folds</font>, <font color="#CC3333">CO raises</font>, <font color="#666666">2 folds</font>, Hero calls.

Flop: (4.40 SB) 8/images/graemlins/diamond.gif, 3/images/graemlins/spade.gif, T/images/graemlins/heart.gif <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">CO bets</font>, <font color="#CC3333">Hero raises</font>, <font color="#CC3333">CO 3-bets</font>, Hero calls.

Turn: (5.20 BB) K/images/graemlins/heart.gif <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">CO bets</font>, Hero calls.

River: (7.20 BB) 8/images/graemlins/spade.gif <font color="#0000FF">(2 players)</font>
Hero checks, CO checks.

Final Pot: 7.20 BB