I too had the same problem.
Got one of these off amazon.
Mine reamer was too large for this application, but this fit the bill! and all for under 10 bucks.
https://www.amazon.com/gp/product/B074TFSS9R/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
Worked Beautifully! Temps are now in high 30C at idle. Was never like that before, I suspect that who ever drilled the holes on these mounts, were off a bit. Just be careful you don't drill too much as you could end up creating a slot! LOL. Easy to do, fit's much better and I get way better cooling now, since the springs don't have to fight the threads. Slides right over the mounting screws like it was suppose to.
Hint: You don't need to remove the entire mount. As I was thinking, there is NO way I'm going to drilling shrap metal next to my case, you can actually slide the metal mounting clip off of the cooler. So, just pull it, slide out the clip, take it out to the shop, enlarge the 4 holes a bit, test fit, clean old compound, reapply thermal paste.
BOOM! enjoy the cooler temps!