No space for that, I'm afraid. I already have two 6Us attached together. I literally have about 10 inches of desk between the Brutes and the PC monitor!
Just for reference, this is the Rack. The two Fansynths don't exist but I'm holding space for them (or something like them, Mutant Modular told me something better is on the way) because this thing gets hot and I'd like my modules to last well into retirement...! I use the rack for generative stuff.