Villain runs 29/13/1 over 100ish hands, no read other than a general passiveness.

I've been isolating the UTG limper a bit and have tangled with him postflop, and have held decent hands at showdown. No real history with the villain himself though.

Party Poker No-Limit Hold'em, $4 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Hero ($485.80)
Button ($390.80)
SB ($493.80)
BB ($390.91)
UTG ($293.66)
MP ($422.50)

Preflop: Hero is CO with 2, A.
UTG calls $4, 1 fold, Hero raises to $18, 2 folds, BB calls $14, UTG folds.

Flop: ($42) 3, 4, 8 (2 players)
BB checks, Hero bets $31, BB calls $31.

Turn: ($104) A (2 players)
BB checks, HalvSame...

Edit: also, thoughts on cbetting vs checking behind the flop?