Here is the deal... In Quebec we have a licence plate rating by cc and anything under 400 is WAY cheaper to plate and insure...The go by model/seriel number on the frames. So anything in a 400cc frame and i'm set I want to built me a little motard for fun rides that would double has a woods machine once in a while. Does the more recent WR450 motor bolt into a WR400 frame? If not, alot of mods would be required? I'm a decent welder/fabricator, I would not be worried about that part but if someone has already been down that path before any hints would be appreciated.