If it doesn't fit, it's cheaper to get another cooler than a case.
But before that, it's not impossible, maybe even likely, that there's no actual problem with the Zalman.
If the fan rotates freely and sounds fine, did you try to reapply thermal paste and reseat the heatsink?
And if not, perhaps try to find a replacement fan of some sort.
Thermal paste was put about half year ago. I am not going to spend money on an old fan. I thought to change my case not only because of the CPU also because my GPU might heating the whole system (it's AMD R9 290) and I thought a new case would solve the CPU problem and the heat, noise as well.
Also I thought that upgrading after 7 years would be nice.
But I will take your suggestion into account, maybe I will just sell it, without any lose, and drill my case for another fan or something like that. I am currently running with 3 X 120 and one of them is wobbling and working really bad (the HDD/SSD fan). Thank you.