How to mount a fan shroud?

Guys I bought a fan shroud from Davescuda and I'm looking to install it this weekend but I can't find any specs/examples of how to mount the brackets to the radiator. I assume some type of cage nut, but I can't find any examples/specs of what will fit the slots properly. If anybody can help me out here I'd appreciate it.

Car is a 65' with the 22" radiator.
Author: BigblueC