the 55-57 had a setback positon for rads on V8 trucks to keep the same space fan-to-rad ....
this shows the setback with the extra sheet metal piece at the top to fill the space [there's additional pieces at bottom] .... the actual
core support is the same, just set back .... the 58-9 was the same rad position
with a shroud on the V8, slightly different core support from 5-7, same rad .... the 55-59 rads are about 21" sq for the finned area with the tank adding about 3-4" more height
regardless of the clip, your rad support has to be basically original in order to support and position all the front sheet metal .... I've seen an assembly manual page of the V8 setup, but can't find it just now
Bill