Linhof makes Hasselblad V adapter for 4x5 cameras with a graflok back (http://www.bhphotovideo.com/c/product/149263-REG/Linhof_001693_Hasselblad_Digital_Back_Adapter.html
). It can be used with digital backs only, not film magazines. I have tried it before, it's fine but not excellent. Now I use a sliding back made by Digital Arts Institute in Japan. It's much easier than the Linhof one.