You can't swap out bell housings on a 727. It's a one piece design and blends with the rest of the transmission body.
You can swap internals between a SB and BB 727 and you can swap tailshafts between 2wds and 4wds.
Ed
You can swap internals between a SB and BB 727 and you can swap tailshafts between 2wds and 4wds.
Ed