Also, the handling will likely not be anything like it was. All having been said, if you are determined, I think one of the Triumph triples would come closest to a decent fit. You'd have to fabricate new lower frame rails (good thing they bolt on) and adapt the upper engine mounts. A triple might be wide enough that you could do away with the engine offset too. Note that the chain is on the other side, so you will have to deal with that.
