http://www.fordification.com/interchange_body.htm
Radiator core support - All '67-'72 F100 thru F350 core supports are physically interchangeable, but there are differences:
Core supports for trucks originally equipped with a 6-cylinder engine have a smaller radiator opening vs. the V8 trucks. A 6-cylinder core support can be modified to fit a V8 radiator.
'73-'79 F100 thru F350 core supports are cosmetically different but will physically fit. Several holes will need to be drilled to mount the '67-'72 grille mounting brackets. F600 supports can also be made to work with a little additional work. Click here for more info.
Aren't the 4x4 core supports (and radiators) different?
I know the 2wd radiator bolts directly to the core support, and IIRC, the 4wd radiator bolts to brackets spot-welded to the core support.
I never noticed this until I offered Heep70 a '73 2wd core support, and his differed in the mounting brackets.
this means the radiators won't swap between 2wd and 4wd trucks without changing the brackets.
I'll try and get pics tomorrow from the 2wd and 4wd trucks I have here