How close, is to close for rad fans to water pump pulley space

How close, is to close for rad fans to water pump pulley space

Looking at the derale fans, I am seeing some rated at 10,000 rpm and they are between 15-18 inch fans

Frnknsteen said
The one I chose was a Derale "Performance" fan. It's rated for 8000 RPM, and has a steel center frame and stainless steel fins

Could you post more details or a picture - cause there are literally 100s of options - so I could narrow the search. And read about flex and mounting distance.