There is some minor difference between '67 and '68-9 radiators and shrouds.
Maybe the shroud mounting holes? But really have no idea. . Maybe ask in cooling what the difference is.
Here's the '68-9 shroud (repro)
View attachment 1715779198
The fan opening is about 20"
View attachment 1715779182
Center of the fan opening is about 10" from the passenger side shroud mounting holes
View attachment 1715779181
Vertically the rightside mounting holes are about 2 1/4" and 15 3/8" about the bottom line.
View attachment 1715779199