could you not run the tubes out the other side, i.e. 180deg flip the block? that way you can route the tubes around the Ram?
i.e. like this guy did: Yes, he is running LP Ram, but if you take a look at where his tubes are routed is what I am pointing out, he is also running chunky ass power cables so with some custom cables you will have even more room.
Is there space to fit them between the radiator and motherboard though? (I'll be placing the fans on top)
The builder of that PC (@Navic) has replied a few times to some of my inquiries on the subreddit and he says that there probably won't be clearance over the ram for AIO tubing if I go with taller ram like the Trident or Ballistix.
That said, if there's space to fit both tubes between the ram and the radiator things may still work out.