Duster bell housing

Four speed and slant, My opinion is it takes a specific slant bell for the 4 speed. but I have been wrong before (once).LOL...,there were 2 #s of such, which I forget. Sems like they were early bells. Rare and $ if you find one.
Almost certain the /6 I took out of my 70 only had the tiny 3 speed bolt pattern but the 72 is hard to see being on blocks but thought maybe since it had the full synchronized trans it might be the one. But you know Chrysler..