KK pre vs unknown nit

1/3 NLHE 9 handed

V - Young white guy I've seen in the room that I forgot is a nit. I have very few hours with him. He's been folding at our table for two hours now and has opened only a few hands, he opened CO over an LPs limp once and I 3B Btn and he folded showing 96s so he can get creative. He's called a few times and 3B once but shown very little. UTG 500$.

H - Has been Lagging it up and shown hands like K7s and AJo for 3bets pre. Not sure if this V would notice. Covers UTG1.

---

V opens 15, H raises to 55 with K♦K♣, folds to V who goes to 180, H tank calls.

Flop 360 - Q♠ J♣ 9♥

V pauses for 30 seconds then jams 320, Hero?