Super 55 In the olden days of gravel roads the mudholes could be so big and deep you had to hit em pretty hard to get thru,those shields would hopefully keep you from drouning out and keep cold mud water off of your hot manifold. I've seen them where when you opened the hood it would be packed full of snow level with the top of the valve cover. I think that was in blizzard of 78 in the midwest,froze 4 ft deep in places !!