Just came across this thread and it is very insane work, congratulations!
I plan to do something similar
May I ask the used cpu block height? One similar block I could find is alphacool eisblock xpx 1u which has 25.5mm height with sideport. it still wouldn't fit in dan a4 with 48mm cpu height constraint, considering 20mm rad+15 mm fan. Then This block should be 13 mm height or less. Is that correct? The cooler master block is intel one, did you have to do modify it fit to the am4?
Thanks a lot, and keep us posted about your awesome work!