After 1200 miles on my lq9 swap my engine developed a metallic tick. The sound only becomes noticeable around 190-200 degrees. My thoughts were a bad lifter, or possibly a bad o ring on the oil pump, aerating the oil. It will be a couple months before I'm able to tear into it and fix it. Does anyone have any experience with this problem on 6.0's? Or any ideas of what it might be? Thanks