73 E body front disc brakes conversion on A body. Where did I mess up?

Am in the process of dry fitting my parts for A body front disc brake conversion. I ****** up. Understood slider style calipers mounted on rear which I am not finding to be the case after fitting lower ball joint. Have 73+ E body spindles and slider style calipers. If true, this means a sway bar is not possible. Can anyone tell me what single piston disc brake calipers, compatible with an A body, mount on rear of spindle (knuckle)? Or what spindle do I need for this conversion?