The '71 351C utilized a different style from what you see on the 72/ models. The '71 351C (2 & 4bl) both used D1AZ-9A603-A, which is a single-piece design sourced from the '71 full-size Ford with a 400 engine. The '72-74 351C used the 2-piece design with the same outer but different inner shields depending if 2 or 4bl.