Right before my exit from the big C I worked two tow trucks cases with this problem. I kinda refused to believe an engine with less than 100k miles was dusted... a couple days later the correct orifice came in and we went and road tested with the manometer...... Both were F650 with 6.7's. one had the bad clamp the other a hose was split and was ingesting. Guy I knew at Ford clued me into the issue. Once we started taking the intake and CAC system down it was very clear what caused it.....