A Body Disc Brake help

I just went over and looked at duster, I took a back wheel off my brothers 66 fury 3 which I know is a big bolt pattern and it fit perfect on front of duster, but I was reading that the big bolt pattern was from 73-76 could this be cause the car was made 9/72 ..? Would I need to use the bottom aarm on switch over ..?. Thanks all for the input

I'm not positive, but I don't think you need the lower arm to do the swap. You might have to have the ball joint, but I think the control arms are the same. If it has sway bar tabs then it would be good to get them too though. You will definitely need the upper control arms to get the big ball joint, and if you can grab the proportioning valve as well.