What kind of riding do you do?
Your going to need alot of stuff if you don't already have it.
Cool head, Pistons of choice, true and weld crank, billet basket, longer swing arm, longer chain, new sprockets, longer brake line, new pipes, bigger carbs, new intakes. The list goes on. Also with a lockup you would be wise to put a over ride in there. Don't have to but it makes shifting ALOT ezer.
Depending on what kind of riding and more importantly howmuch $$$ you have to spend there might be better options for you.
If you really want a Cub, I am trying to sell my bike