That's correct Vall, the axles have to be built somewhere else. The narrowing jig justs helps keep everything straight when narrowing the housing.
Steve did you get one from mittler bros ? How do you like yours ? Pros and cons to it ? The only thing I didn't understand that is not included are 2 locking collars to put on the outside discs to keep everything "sammiched" together. I'll have to get a couple of them made.