Speedometer cable

I got a replacement speedo cable from oreilly 's however the trans end on the cable I got was not large enough to screw onto the tailshaft housing.

I know these are year specific, does anyone know what years had the "larger" end for the trans?

I have a 70 dart, 340/904 but used to be /6 car. something tells me that this trans isn't from the same year.

Thanks again.