Thanks all for the good advice! I did recently freshen up the trans in car, has deep pan with drain bolt and shift kit, did a fresh tailshaft bushing.. but I will absolutely take the opportunity to do the front seal and shift shaft seal. And I have a spare slip yoke to pop in there, good idea.
Just so I understand, is this just too keep the converter from falling out while I am wrestling with/balancing the transmission on the jack... then when I get it in position and ready to mate back up, I remove the bolt?