400NL - What's the best river plan here?

[spivey]

Villain is a 38/14/0.5 with an ABS of 28% over 60 hands, WTSD of 35. I've been raising a fair amount of villain's limps, and probably thinks I bluff too much - he flatted preflop KK from the BB against my MP open, got a river bet out of it when I hit a medium pair on the river. Flop checked through, turn was an ace and checked through on that hand.

Full Tilt Poker, $2/$4 NL Hold'em Cash Game, 6 Players
LeggoPoker.com - Hand History Converter

BTN: $807.90
SB: $630.30
Hero (BB): $404
UTG: $432.80
MP: $134.80
CO: $785.10

Pre-Flop: T[img]/images/graemlins/diamond.gif[/img] 6[img]/images/graemlins/spade.gif[/img] dealt to Hero (BB)
3 folds, BTN calls $4, SB folds, Hero checks

Flop: ($10) T[img]/images/graemlins/spade.gif[/img] 3[img]/images/graemlins/diamond.gif[/img] 6[img]/images/graemlins/heart.gif[/img] (2 Players)
Hero bets $8, BTN calls $8

Turn: ($26) 7[img]/images/graemlins/diamond.gif[/img] (2 Players)
Hero bets $20, BTN calls $20

River: ($66) T[img]/images/graemlins/club.gif[/img] (2 Players)
Hero?

I think he could be calling down here with holdings as weak as 22 on flop and turn. What's the best plan? Bet small ($30) to get value from [censored] holdings and also to get raised by T's? Bet large ($50-60) because he may call with [censored] holdings anyways, and still may raise with T. Is CRAI an option here?