My experiance suggests that you'll be pretty close with stock jetting. Hard to imagine that you would need 70s (comes with 62 or 63) in the center unless you have the mixture screws on the outboard cabs nearly closed.
Never had to go above 65's on this and it is not stock,runs like a clock !
Hard to imagine that you would need 70s (comes with 62 or 63) in the center unless you have the mixture screws on the outboard cabs nearly closed. 
