I have installed a be quiet dark rock pro 4, which works perfectly. The memory chips are very close to the bottom. There is only about 2mm left.
Another tip: I have a Ryzen 9 3900X, which I overclock to all-core 4250Mhz. However, the CPU temp is reaching its limits. Sometimes I have over 100 degrees. I will now switch to a water cooling system, because the Ryzen can do much more, but needs appropriate cooling. Air coolers quickly reach their limits when overclocking.