Longer tail shafts typically on the truck AOD.No different internals but the later model AOD's had refinements(89 on) better lubrication,stamped steel drums,better valve body,etc.These arent known as difficult transes to rebuild.You could do it with a rebuild video and lip-seal installers.Use a new torque converter and flush out all lines completely.Make sure torque converter is fully seated on install.Make sure TV cable is adjusted correctly or it will burn up instantly.