Yes another disc brake question

So i have recently discovered that my k frame in my 74 dart is the earlier style with the biscut style motor mounts. So my question is what do i need to do the swap. Do i need new lower control arms? or do i just need to buy the spindle, rotors, calipers, proportioning vavle and misc. pads and such. More worried about if i need to get new control arms. Also i would like to stick with the sbp. Thanks.