We fired Dave’s Banshee up last week and I felt the same vibration in the bars. I was able to get rid of most of it by adjusting the jetting. He’s running the same porting you are with a 21cc cool head, CPI pipes, V-Force 4 reeds, stock air box and stock carbs. I rode it last weekend and it scared the living crap out of me. Funny thing is I know I can dial it in even better. I’ll be messing with it again this weekend. We’re running 25 pilots ( going to 27.5 next) air screw out 2 turns, Vito’s needles with the clip in the top position and 350 mains. It seems to have a small dead spot just off the pilot but pulls like crazy as soon as it gets into the mids. It’s almost like it wants leaner slides. Time to break out the files.