Opponent is a 37/9 3betting 2 times out of 79 (over 200 hands). Not particular sticky post, infact, he's snapfolding every time I cbet. Also when he does call on the flop is folding 4 of out 8 times on the turn.

I'm betting flop and turn for clear value and going for another clear value bet on the river, but he donks out.
Are you raising? As you can see I'm not, since I figure out that sets of 5s and 3s are unlikely. JJ and TT are probable, QQ imo less likely, AK is likely also since if he's so passive he can surely flat pre with those hands.

Assuming he's calling with sets and straights
http://www.power-equilab.com
Board: JhThQd5c3h
Equity Win Tie
MP2 60.61% 60.61% 0.00% { Ks9s }
MP3 39.39% 39.39% 0.00% { QQ-TT, AKs, 98s, AKo, 98o }

Well, in game I didn't realized 98 is in villain range I admit that, however in the range above I assumed he's calling a raise with a set, which isn't 100% sure.

If we remove AKs from the range above, weighting a bit his strong holding, we are now at
http://www.power-equilab.com
Board: JhThQd5c3h
Equity Win Tie
MP2 52.38% 52.38% 0.00% { Ks9s }
MP3 47.62% 47.62% 0.00% { 98s, AKo, 98o }

What's your thoughts? Too nitty?