The popping is because it is too lean. I am confused as to why you didnt have problems at sea level. It would run leaner at sea level than at higher elevations. Taking the shims out of the needles makes it leaner in the midrange. and if you lower the jet size, that will make it leaner at the topend. That is why I wouldnt change anything until you got home. I would then put in bigger pilots (45's ) so that you can run with it about 2.5 turns out instead of 3.5, you are getting close to the max you can turn the screws out now. The popping on decel has mostly to do with the idle circuit. ( the screws and pilot jets ) When you back out of the throttle and there is too much air and not enough fuel in the idle circuit, then it pops.
Mark
