Hy busterswt, I've never done this job before but here goes with some suggestions which may help, T.H.400s in trucks have their output yokes retained by a bolt in the center of the yoke, is there one on this tranny, from the pics it looks as though there may be a flange mounting of the output yoke to the brake drum area, try removing those bolts and pulling off the yoke that may reveal what is bolted to the output shaft and holding everything together, hope some of this helps.
