I think the answer you're looking for can be found in Swifter's thread regarding VINs lining up with your insurance paperwork. From what I've read, your numbers can be transferred over, but I highly doubt you can do it yourself. I think you need to call the DMV and tell them that you have a car that needs the frame replaced, and that you need the numbers transferred to the new frame. They'll send a guy over who will either supervise you cutting the numbers off your old frame and attatching them to the new one, or else they'll give you a new tag to put on your new frame, but then I believe the old frame (or at least the numbers on it) have to be destroyed. Once this is done, they'll sign off on it. Bottom line is that you can't have two frames with the same number on them, especially if you do it yourself without someone from the state signing off on it. That's what I got from Swifter's explanation, anyways.