Head might not fit, the dome is a different diameter, you'll find out.lol
You might not need a new crank but certainly need a rebuild or at the very least new seals.
With the stock exhaust you won't see much improvement. Maybe even less power than stock. Gonna be super restrive
Jetting, buy the next 5 sizes up from what you have and start with the biggest, go down until the four stroking juuuussst stops.