He's Picked up a real hand here, Ace Ace

Lost the hand history. I have pocket aces with blinds at 100/200, Partypoker $22 MTT. 415 people. No reads on the villain who calls my raise to 575.

He's right behind me, i'm 3rd to act.

Flop comes: Kd 8d 7 spades

Pot is 1450.

I bet 850. Villain who has the same amount of chips as me (4100) pushes.

How would you play the flop as far as betting. What about raising preflop. Instacall here, right?