I believe the '67 is by itself as a one year only. The '68 may be close, but I believe it is different. The others years are definitely different.
Also, the Hollander Interchange is a great book. I have 4 of them. But they do not list many of the smaller parts and I believe the Radiator Support is one of them. The Radiator itself, yes, but not the Support.
To find a good one, you will need to go used.
The only one I have available has some rust issues.
Try at some dryer states like AZ. Desert Valley Auto would be a good place to start.
-Parting Out over 75 '58 to '73 Full Size Chevy Cars-
-National Impala Association
-Vintage Chevrolet Club of America