OK, you don't need an adapter
You can slide the inner column out the 2.75 inches needed to meet the manual box and still have 100percent engagement inside the column.
You will need a manual steering coupler for the larger spline on the new box.
I have those for $25 plus shipping.
DISCLAIMER. Unless you have actually, with your own two hands, taken one of these columns apart, spare this guy your second hand experience and wives tales.