Villain is 13/10/2.6

PokerStars No-Limit Hold'em, $1.00 BB (9 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

saw flop|saw showdown

SB ($78.75)
BB ($166.15)
UTG ($139.70)
UTG+1 ($98.50)
Hero ($147.50)
MP2 ($138.25)
MP3 ($105.40)
CO ($57.95)
Button ($118.10)

Preflop: Hero is MP1 with 7, 8.
UTG raises to $3, 1 fold, Hero calls $3, 3 folds, Button calls $3, SB calls $2.50, 1 fold.

Flop: ($13) 3, 6, T (4 players)
SB checks, UTG bets $8, Hero calls $8, Button folds, SB folds.

Turn: ($29) 5 (2 players)
UTG checks, Hero bets $22.5, UTG calls $22.50.

River: ($74) 5 (2 players)
UTG checks, Hero bets $49, UTG calls $49.

Final Pot: $172

Results in white below:
UTG doesn't show.
Hero has 7h 8h (one pair, fives).
Outcome: Hero wins $172.

I thought he could laydown an overpair on this board. Bigger river bet?? Shove??