Hate to kill your good time here, but the 54 clip is different then a 52 clip. The hood line is at a different level and the fenders mount differently. I think the fit at the doors will be the most troublesome. A 54 (55 and 56) fender has 3" or 4" wide flanges at the rear of the fender, 90 degrees to the fender surface that run from the top of the fender to the bottom. Those flanges are bolted to extensions welded to the firewall . You open the door to gain access to the fender bolts. (I just know I don't have any pictures here anymore.) This picture is a 54. Notice how high the fender line is on the door and the shape of the nose?

A 52 (48 up to 53) fender bolts to a 6" long angle plate that bolts to horizontal plates in the front fenders. Those angles then bolt into the side of the firewall/cab 90 degrees to the front of the firewall. You access the angle bolts from inside the cab.

All that said, make sure which truck (and clip) you actually have. I think this era truck has the years confused more then any other Dodge trucks ever built. Gene