What is the exit number off I-40 coming from the west (asheville)?

123B The exit for 123A veers right, stay left and 123B circles around to right, just past 123A

123b

Exit 123 B

Steven is correct, they are initially the same exit. Once you exit I-40 by following Steven's suggestion you are put directly on 321. Stay right and take the very next exit off 321. This puts you on to 70. If you miss the exit to 70 you can still get there it just becomes a bit harder.