I had originally experienced an interference problem between the mixture arm, airbox and lower cowling scoop. I replaced the servo offset mixture arm with a straight arm from Superior Airmotive. After more installation work, I decided to go back with the offset arm (exchanged again) and fabricate a "bubble" on the side of the scoop to allow room for the lever to (1) have full throw without contacting the airbox or scoop, and (2) have enough room to allow for engine shake.