...............and it's highly recommended you not weld the joints on, the heat has a high probability of damaging the bearings and seals. If you don't go with the splined ones then roll pin them, two pins per collar, 90 degree separation.

You may be able to use some from an Astro van, but only if they are very low miler. The new ones would probably cost as much as Flaming River or Borgeson.......either of which would be my choice as with Dave.