Hate to be the bearer of bad news but I think you really need a 280mm aio for the 3950X
It outputs just too much heat for a 120mm aio
You can get a 240 or 360 aio, but it might manage better I’d you went custom loop
I found this thread for water cooling in this case, he did a custom loop but I’m sure it’ll help you for aio
I think it might go better if the rad is intake