[Jack21]

Have exact same fan, and like you, didn't buy into the plastic pull-through mounts. Seemed like a sure radiator destroyer.

Believe local Trak or Pep Boys had electric fan mounting bracket that mounted the fan, then mounted to the top and bottom of the radiator. Used weatherstripping on the mount to rad face. Radiator has aluminum top & bottom and I wanted steel to secure the mount to. Sawed up some shelving wall brackets and attached the pieces to the rad with marine epoxy. Then mounted the rad bracket with sheet metal screws. Good & solid.

You could easily make a bracket with aluminum bar stock, but use angle or channel for stiffness and rigidity.