I am no expert in this....so I asked Dan Lockwood (on this forum) some time ago. He knows his stuff. His suggestion was a '99/'06 Harley Twin Cam "B" motor with counterbalance shafts as this has the same case bolt pattern, crank splines and less vibration. These can be up to 124cu in and 120 bhp, so no problems with power! If Dan is about he may give more suggestions. I am sure that if it becomes a problem with the X-Wedge then there will be solutions such as this. The M3W is not a cheap car and people will spend money on them to get them going again.