Good question, actually.
I\'m pretty sure the rules for Chaos Dwarfs (Ravaging Hordes, I think) aren\'t applicable for WFB\'s current edition. You might, however, rebase your Dwarves on 25mm bases and, when you properly \"chaos\" them up, declare them as either Marauders or even Chaos Warriors (depending on their gear). Might give an interesting fluff aspect to your Chaos force. I myself used some appropriately painted Dwarves and Chaos Warriors as Ghosts and Wights, respectively, for my Undead army. So basically, I\'d say go for it, although you might have problems with ranged weapons. And since Dwarves and Chaos Dwarves do look quite different, rather explain them as some kind of corrupted and/or defector Dwarves than as \"real\" Chaos Dwarves.
Hope that helps,
MirzA