1947-1950 Chevy radiator supports only had 1 frame mounting pad in the middle of the support with no extra bracing.... { 1/2 ton trucks only }.
GM realized that they had a problem with front end flex & the radiator supports were cracking under that stress .
In 1951 GM upgraded the radiator support to 2 frame mounting pads with additional X bracing & an extra rod on the lower portion of the support to prevent any further flexing & cracking.
I do believe that the upgrade took longer to be applied to the 3/4 & 1 ton trucks as they had a stiffer frame with closer frame rails which prevented the flexing associated with the wide frame railed 1/2 ton trucks.
The 1951-1955.1 radiator supports are superior to the 1947-1950 supports.
