If you have a Pro-flo flange for your filter try taking the airbox cover off or drop 2-3 sizes in your mains.
A few years ago I was running 270's in mine with Fatties, snorkel off with 6 one inch vents cut in cover,FMF Ram Valves, and case matched - at sea level and it worked great. I found it worked better with 27.5 pilots thenit did with the 30s in it.