5-10: K-10 on K-K-5 board. Alternative line?

Hi! I rarely post. Mainly because the hands i play are boring. This one may not be so exciting either.. But here goes:

Playing 6-handed. effective stacks are 1700. utg limps and its folded to me on the button and i raise to 40 with K [img]/images/graemlins/heart.gif[/img]-10 [img]/images/graemlins/heart.gif[/img]. BB calls and utg folds.
BB is aggressive, tricky and good.

flopp(90): K-K-5r

Check, i pot, reraises to 240, i call 150.

Turn(570): Ac making two clubs on the board.

check,check

River(570) is an offsuit 6. BB bets 200 and i just call.

Should i raise for value on the river? Turn play? what is BBs holding? [img]/images/graemlins/confused.gif[/img]