I don't think stacking them will hurt very much, except if the Blowtorch has a phono stage. That's the circuitry you want most to keep away from power supplies. I would ultimately recommend separating them, though, if you can, in order to avoid audiophilia nervosa...
CTC Blowtorch
I have recently made a deal to acquire a CTC Blowtorch, which has been sort of a long term dream of mine ever since I heard Bob Crump's unit some years back. The Blowtorch has separate main stage and power supply boxes. I will, at least temporarily, be somewhat short on rack space. Does anyone have experience to share regarding stacking the two boxes? Can I expect any sonic degradation from doing so? My suspicion is probably not, given the sheer amount of aluminum separating the two, but would be most interested in hearing others' observations.