Yeah, if you are ditching the stock airbox lid, it should be jetted. Nothing drastic, maybe up one size on the main jet, back the fuel screw out a little, and see how it runs. I don't think you'll need to mess with the needle but you won't know til you try it.
Does anyone have a jet size the recommend? most riding will be done around 3000 to 6000 feet elevation. Again it has an FMF powercore 4 and a K&N filter with stock airbox minus the lid
I'm pretty damn sure 150 is going to be too much at that elevation. Stock might actually be pretty good at that high of an elevation with your mods but I've never done any work on stuff at high elevations so it's mostly a guess. I would think a 147.5 would be the max.