I believe the reason for the .357 Impact has to do with the fact that they're upgrading the Impact's plenum size, and a few other little internal bits and bobs. Given the way the Crown is designed, this would be quite challenging, although presumably an auxiliary plenum could be utilized. While I have no great insider knowledge, I guess I'd say it is probably rather unlikely to see a .357 Crown in the near future without at least some additional parts/modifications to the plumbing.