I mounted the fan to the mount we fabbed up. I don't care for the skinny plastic mounting things that are included with the fan. Hence the mount. If you look in the picture you'll see where I used 1/4-20 bolts to mount the fan.

I needed to use some nylon spacers to mount the fan as it bowed up the sheet metal without them. Used some window foam to seal the fan to the sheet metal. Decided not to use the dimple die to make more holes in the mount as I felt that would end up just allowing the air to flow out those holes rather than thru the radiator. If it turns out I have highway speed cooling issues I will revisit this. Here's the mount ready for the fan.