It might be possible, but I've decided that it's not worth the trouble that it would take to try to cram it in there. I'd rather have the electrocouplers, command, and sound. The smoke was going to be icing on the cake if it made sense. It would take plumbing, and I don't know how well it would work. To do it right, it would have to come out of both stacks. It would also be a tight fit, even for the HO smoke unit I was thinking of.