Are you saying to ditch the idea of mating the RF1A and just use a Dana 44? or adapt the RF1A, but make sure to use the gear driven one.
Use the gear drive case if you want pass. drop. Marlin makes an adapter and so does inchworm. If you want to clock it make sure the marlin adapter clocks in the direction you want. I used the inchworm adapter and it will clock in either direction. Don't be afraid to buy from inchworm Jim is a great guy and his customer service is top notch.