The metal strips edge is lower than the center where the bolts pass through. If you don,t cut the edge grooves you will pull the center of the strip down. You could put a spacer ,washer, between the stripand wood. You will see the end profile of the strip when you drop the tail gate. Also I think the center syrips will be higher than the edge ones welded to the bed side. Its alooks thing. You can cut thegrooves with a router or table saw. I would like them recessed as orig.
