Here's a link to hitch design and some various service manuals.

The hitch design came from this board. My thoughts are to modify for a 2" receiver simply so that I don't need to have smaller sized hitches lying around. Of course, that would require restraint and not hooking too heavy a load just because you can put a 2" ball on the thing.

https://www.dropbox.com/sh/5wgmveryif2ijnh/AABn9OEwrQQHYx224rbwS-ZAa?dl=0

Take all you want. I'll change the links later if I decide to.

Here are some more mostly trans manuals that I found floating around on the web and downloaded (legally).

https://www.dropbox.com/sh/leojhxboood2bin/AABByZ86RMDHJ5X5lVDEQXtGa?dl=0

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.