So my pc is playing up but river was 9s, villain checks, pot is 593420, villain has 416412 remaining.

I know a lot of you guys would have checked pre however villain is playing very passively, I believed it to be a good spot to apply pressure.
The tournament average stack was 640000 with 10 left and there were two stacks under 100000. On opr his biggest cash to date was >$200 and by laddering up from 10th to 8th he would have improved his biggest cash.

Flop I thought was an easy c bet with the gut shot, I was also assuming a large portion of his range would include broadways, connecters and weak aces.

Turn was pretty amazing I thought as we turn the double gut shot, we block his straights with the 6 and we can safely keep repping over pairs, I was thinking of betting a larger sizing but wanted to maximize fold equity on safe rivers for us to shove.

River I think we should shove, all his one pair with draws have missed, plus overs with flush draw. We have all over pairs in our range plus sets of 88 99 which villain doesn't have. Also believed villain SHOULD be over folding given icm pressure. The negative is we have a very workable stack if we give up and down to 10bb if called. The tournament wasn't super tough.

Any ideas of how to play this post flop after our pre flop action would be great. If anyone is curious I shoved, he thought for 5-10 seconds and called with A5dd. Gutted!