The 53 didn't have the cross braces so the 53 deflectors don't have the reliefs for the rods.
IMHO It would be much better to modify the deflectors or find a set of 54-55 deflectors than to cut off the braces. The entire front end hangs off the radiator horseshoe and it is critical to the fit and alignment.
53 was the first year where all the sheetmetal hung off the radiator support. Ford must have discovered it needed stiffening since they added the X bracing and continued to use it at least thru 56.
The 54-56 would work for you and your grill, if you wanted to use the 56 grill (only chrome one and had the recessed headlights to remove the bug eyed look) then you would need the 56 only ones. The 53's could be modified.
A square will never be as ridged as one with triangulated bracing. All that sheet metal hanging a ways away from that relatively narrow and flexible (if unbraced) support can exert a lot of leverage on that frame. Ford was not known for adding even one extra bolt if it wasn't absolutely needed, so those braces and the associated extra stamping on the deflectors were put there for a definite reason.
I removed the rivets on the top end of my cross brace rods and welded them farther into the "horse collar" to give me the clearance I needed. That may give you the clearance you need to use your early air dams.