D-Body Kelsey Hayes Pin Style Caliper Adapter

I am hoping to upgrade the brakes on my 71 dart which currently has drums.. I am looking for some confirmation/help on a couple of things. My hard parts plan is -

76 - A body spindles ( upgrading to BBJ tubular uppers )
11.75 rotors off of an F M or J body
Calipers off of a 70 Imperial Kelsey Hayes Pin Style Caliper

I am running a factory sway bar so I think i need to stay with rear mount calipers..
Do I need a special adapter or is there a factory part for the caliper mount?