FYI, you don't need that adapter. Just pull the shaft out of the steering column, it is telescopic. The only thing holding it from telescoping is some plastic that is molded into a hole or a pair of holes that is drilled through both the inner and outer shaft. Whack the shaft with a hammer and the plastic shears right off. Then you can extend the length of the shaft by telescoping it longer. The holes for the manual box length should already be drilled. Then just put an aluminum bolt in one of them or fill the holes with a hot glue gun or something and put the column back together. Then you don't have an adapter cluttering up your engine compartment.
But you do have to work under the dash to get the column out.