A little history here, when the '47 AD trucks were released Chevrolet only thought of the system as being three points.
https://www.flickr.com/photos/advance-design_parts_co/17244736685/in/album-72157651718017649/
Later as trucks started to show front end sheet metal cracking and stress problems the mounts were re-engineered and correctly described as a 5-point system. The radiator mount truly functions as another mounting point and has been modified over model years as well.
https://www.flickr.com/photos/advance-design_parts_co/12315088635/in/album-72157640522200463/
https://www.flickr.com/photos/advance-design_parts_co/8350452080/in/album-72157632440242503/
The early parts have been out of production for years and NOS are very rare. The revised mounts are now reproduced by vendors or available often in the Swap Meet section. You will save yourself a lot of time and searching if you retrofit now, unless you are looking for a correct restoration on a 47-mid 49 it is a good set-up. None of the vendor kits are correct for the cab bumpers (originals shown below).
https://www.flickr.com/photos/advance-design_parts_co/8129470535/in/album-72157631868452754/

1950 Chevrolet 3/4-Ton 3600
More pictures on Flickr