3bet larger pre, people are not going to be folding to 3bets this early, this deep, so you can make it 225 and extract more value.
Flop is good, why are we checking this turn? The 3 is a total blank card and we have an overpair, I would bet 300 on this turn.
River is gross. Villain is making a polarized shove and our range is pretty capped when we check the turn. This however is a freeroll, so perhaps we will see people spaz out on this river with 88+? On the other hand, our opponent can easily have 55,66,44,33,77,65 and it's hard to see what air hands he is check/calling the flop with. Personally I feel this is a sigh fold.