what size carb do i need?

I agree, 750 to 850 should work

What about gears, converter, tire size and weight ?
My dart has 488 gears. i have not got the converter yet.Im thinking 3500 to 4000 i still wood like to drive it on the street .the tires are going to be either 28 or 29 and i dont know the weight yet.im thinking from 3000 to 3300.