If those strips have holes punched for 47-53 beds, I would recommend using them in a 47-53 bed. If you are bound to use them in the 54, it could be done, but most holes would be in the wrong places. This affects at least your cross sill placement, alignment to existing angle strips, bed to frame hole locations, and front bed panel mounting holes. Hold them beside your 54 angle strips on your bed sides to see the differences.
Mar-Ktech