Lockups started before the overdrives, The first overdrives came out in 89 and where optional. Regardless the OP want's to "morph" a 727 and a overdrive to use in a diesel. You would have to cut the back of the transmission and weld on a section from a od trans to bolt the od unit to it. Then you have the output shaft to deal with and how are you going to activate the od?(it's electric over hydraulic) Then hope you have everything aligned perfectly. More work than just finding a od that will bolt to a diesel.