I'm not a fan of the shove here (although I haven't clicked the spolier button). You are not going to get called by anything except a flush or maybe AK. KK can't be in UTG range as he limped initially.
I don't see the shove as being a winning play, although it may work when you opponent doesn't have the flush. You are going to win the $250 pot, but will lose a $1050 pot if he has the flush/AK/set.
With a villian that is playing aggressively with marginal hands, you can't take a hand like 6h7h (or any two hearts) out of his range; this is a losing play.
I'm somewhat surprised AK called here, but I have seen more amateur moves than that in my experience with LLSNL. Pick a better spot to make you shove, the pot just wasn't big enough IMO to justify the shove/steal here.
i think i need to just go nut peddle and check to you guys.
what range do you really rep here when you shove. if you have Axhh, against a known bluffer, whom you just cold called his raise post flop and now got a check on the turn, are you really SHOVING the nuts here.
(by his call i guess we should but i doubt anyone here does it in practice, and for good reason you dont)
This play would have been good vs a more conservative player. From your description, villain has little clue about relative hand strength, and is overall spewy. I think you get called a lot here. Against some old nit, I like this play.