Get 27.5 pilots. 260 mains good maybe a touch rich at your elevation with your airbox lid on. Needle clip middle groove is good. A larger pilot will add fuel to the idle circuit. Also you want to fine tune with your airscrews. You want to be able to blip your throttle and it should be snappy off idle. Airscrews in adds fuel. Airscrews out removes fuel. Also you want to make sure your carbs are sync’d at idle and part throttle. There are you tube vids for that. Do you still have the TORS system installed? Do you have a Clymers service manual? After you’re all good, you might want to experiment and move the needle clips up 1 groove to lean it out a touch through the midrange due to your elevation, but if it gets any colder, don’t. A rich tune is a sluggish tune, lean is mean! Sent from my iPhone using Tapatalk