Hi Bart, in answer to your question it is not the clearance inside the case but the connection to the fan header on the motherboard is not standard with Dell machines. The reason that I was getting an error was because the Noctua fan was not ramping up to the speed the Dell cooler fan would so it threw up an error. My suggestion is that you stay with the stock cooler and then get a SATA power male to two fan header splitter cable and put some fans to draw more air in from outside the case. I sold my 7020SFF with the stock cooler and a GTX 1050ti. I have the Fan header splitters as I never used them and have forunately managed to build a couple of PCs from the ground up. Dell did you a favour giving you the 24 pin motherboard power header, I also have the 24 to 8 eight pin adapter. If you need the fan splitters you can have them if you don't mind paying the postage. My advice to you is leave that motherboard and find one from EVGA, Asus, MSI, ASRock, as these will not restrict your build. Secondhand parts on eBay are pretty reliable, change your case as Dell rivets their motherboards in and new cases are not expensive. Get your components so you can have room to upgrade when finances allow. I have just sold a PC I put together with an i7 4790K, so you will need a good Z97 board the ASRock Z97 Extreme 6 is what I had. The rest of my build is as follows: Corsair Carbide 275R case,Corsair TX-M650 PSU, Noctua NH-L12S cooler, 16GB Corsair Dominator Platinum DDR3 1866MHz RAM, ASRock Z97 Extreme 6 Motherboard,Intel core i7 4790K CPU, MSI GeForce RTX 2060 Super Ventus OC GPU, Windows 10 Pro. I hope that this helps, get in touch if you want the SATA fan splitters, note when powered by SATA they will run at full speed only.