I think my brother might have a new 41 and 39 tooth.
If your interested let me know and I will talk to him
to see exactly what he has and what he wants for them.
Both those sizes should work with your stock length chain,
if your around the center of swing arm axle union.
If you just go one day you will probably get 8-10 runs on Sat. and
8-12 on Sun. If you plan on changing a sprocket, better do it during
lunch or Sat evening, Sun morning.