Hey,Chevy Duty. I ordered a Radiator Support,(part number 78-526)and my headlamp adjusting nuts were to small for your Radiator Support! Why are your Radiator Support holes to big for my nuts? Do your nuts fit in your Radiator Supports?
You might need to get the 48-935 ajusting nuts. That radiator support covers from 73-80 and I believe that the support takes the 79-80 style nuts.