[cfd_engineer]

Problem found. It was my overdrive shaft. The splines on the end had stripped off so I wasn't engaging the overdrive clutches. Apparently this is pretty much commonplace since on earlier transmissions the splines weren't heat treated all that well. The downside is that the transmission was pretty worn out and also with the metal shavings associated with the shaft splines sheared, so I needed it replaced with a remanufactured one. That is in process as I speak. Hope this helps someone