Yep, it in my 71 chassis manual, it’s also cool watching the old service videos like Mike posted. I had the same issue back last spring when I got my 833 back from a old school guy in Portland that has only built 4 speed for the last 40 years. He was unaware of the side case shift to free up reverse until I showed him the book and the video. I just un-torqued and kept bolts tight, tapped the side case up and it fixed it.
