Tranny swap from auto to 3 or 4 speed

I have a '74 Duster in which I would like to replace the automatic transmission with a manual, either 3 or 4 speed. Can anyone inform me as to which cars I can scavage parts from to make this swap? My Duster has the slant 6 motor. I would like to find a parts car that I could get everything I would need from the bellhousing back as well as the steering column and shift linkage. I have heard that Dusters, Valiants, even Barracudas interchange but what about other Mopars with the slant 6? Any information will be appreciated.
Thanks,
Scott:newb: