I found out the lock out cam for my selectro hubs was broken on the drivers side.
I did find a Derlin replacement part.
QU50160 2-5/8" OD lockout hub cam for Selectro and Dualmatic hubs. Black plastic replacement for failure-prone pot metal cams on 1980-1991 Dodge HD.
torqueking.com
And I started my disc brake conversion on the drivers side using the track kick kit from Brennan's Garage.
Only cancerous rust in my tub was in the under seat storage box, and the side steps. So I cut that all out including the had channel and will be working on that shortly as well. I got some 2” rectangle tubing for replacing the rotted hat channel.
One other thing, the drums I’m taking off. Are they worth saving/trying to sell or just donate to the scrap Pile?
Should I be too worried about the rust on the tops of the gears on the sm420? I plan to clean them up. With a wire brush, maybe some OOOO steel wool as well.