What length of transmission do I need for 71 duster?

An A Body 4 speed uses the same length drive shaft as a 904 Auto Trans. I'm pretty sure the HD 230 3 speed for an A Body is the same length as the 4 speed but not sure. There are a230 versions for B and E bodys that are longer with the shifter locations for those bodies. Darts use a longer driveshaft than Barracuda, Duster, and Valiants.