Durron, I agree with your estimate of his range.

However, I think I'm going broke this hand if he has JJ+. I would checkraise the flop to 750, commiting me to the pot but giving him a chance to make an error with his overs. With the rest going in on the turn.

The turn is a bit scary, but only improves his hand if he has AQ, QQ. After he checks the turn you can narrow his hands down to 77-JJ or AK, with AK being most likely in my opinion.

Given all your action I would be reluctant to call more than T240 on the river (his orginal flop bet), so I'm likely folding. It's unlikely he would beat out his 77-JJ here.