if you are gonna go with a 4mill cub, you will need a new crank, (hot rods cranks come welded) different domes for your head (cut for your bore and stroke) bigger carbs, stock will work but you will be starving your motor so bad it woun't be funny, different pipes (shearers are my top choose) cpis second, your vf2's will work, gonna need bigger filters when you get bigger carbs, be looking for a longer swing arm, I still have to be careful with an 8 over swinger, lock up clutch for sure. different pistions depending on bore size. I would stick with race fuel cause you can run more compresion and more timing.
let me know if you have any more questions I can help you with.
good luck