I am running the Supertrapp/K&N/Outerwear, needle on the 2nd notch and a 148 main. I just returned from Little Sahara, Ut and the Piute trails. I took the air box lid off and it ran just fine. Climbed Sand Mtn. (700'tall) and the base camp is around 5000'. Then rode the Puite trail around Marysvale carrying my wife from 5000' to 11,000'. It is 700' where I live. I would like to know what you end up with.