The 54 filler panels must have more clearance for the new metal surround around the park lamps
So you could likely mount the 54 onto earlier trucks and have a bigger gap between the panel and front end sheet metal however you can’t go the other way
The 47-53 will crash into that new metal face below the park lamps
-s
I'm not real familiar with the 54-55 grilles, so you're probably right. I assume someone could modify an earlier filler panel for more clearance if they REALLY couldn't find the proper one. It's just metal.
But the OP hasn't been back to tell us what he needs.
