Suicide bluff?

MP1 is a solid player: 18/11/inf @ 143 hands

Full Tilt Poker $0.25/$0.50 No Limit Hold'em - 8 players - http://www.thehandconverter.com/hands/348593
The Official DeucesCracked.com Hand History Converter

Hero (SB): $83.95
BB: $7.50
UTG: $24.80
UTG+1: $10.00
MP1: $72.55
MP2: $37.00
CO: $20.05
BTN: $57.00

Pre Flop: ($0.75) Hero is SB with 3c 3d
2 folds, MP1 raises to $1.50, 3 folds, Hero calls $1.25, 1 fold

Flop: ($3.50) 7h Th 6c (2 players)
Hero bets $2, MP1 calls $2
Standard cbet

Turn: ($7.50) Kh (2 players)
Hero checks, MP1 checks
This is the scare card for a multitude of reasons: He cbets the flop and I call. Now a K connects well with his range from MP1; AK, KQ are possibilities. His check through tells me pretty well that the K did not help him. I also believe at this point that the heart did not help him either.

River: ($7.50) 8h (2 players)
Hero bets $1.50, MP1 requests TIME, MP1 folds
I am not quite sure where I am here. I am pretty certain that he does not have a heart. I am also pretty certain that he does not have a set. I am unsure as to what he has: 22-55 are within the realm of possibilities, JJ, QQ less likely, and AQ, AJ. I put out what looks to be a small value bet, which is truly a "call me" bet (which for most opponents is probably about $2.00 too low, but I didn't really want to dump more money into the hand in the event my read was incorrect), but I really don't want him to call me. He obviously knows he does not have a heart, and any heart I have beats him right here. Therefore, after deliberation, he begrudgingly folds.

Final Pot: $7.50
Hero wins $7.15
(Rake: $0.35)