Looks like I am missing a part, the "thrust washer"? Is this a difficult to find part locally or is it an online order you think? Here is Lugnutz pic from his 63 assembly pics. I would think its still needed for a 66 with an automatic.
I don't see it listed as a part to purchase on lmc
https://www.lmctruck.com/1960-66-che...umn-components