Post #2, the last photo. Did you replace the transmission mount? If so, what did you use? I'm finishing up the engine in my 82 D150, also slant and 833 OD. I can't find a correct trans mount to save my life.
I used the OE transmission cross mount, for the rubber cushion, back then I was buying a lot of parts from : NAPA, Autozone, RockAuto.
Are you needing the cross brace or the rubber mount?